Research Guides List | Databases List

The end goal of legal research is often to discover relevant primary sources of law like statutes, judicial decisions or administrative rulings. Primary sources are official statements of what the law is, and they are the documents that have binding legal authority.  

While it is possible to search primary law directly, it is often a better idea to start with secondary sources. Secondary sources are all of the research materials that are derived from primary law. Secondary sources provide analysis, commentary or a restatement of the law. You can use secondary sources to introduce yourself to a new area of the law, look up key terms and technical jargon, find primary sources of the law that are relevant to your question, and provide persuasive authority for your argument. In fact, for some questions, you will discover that a secondary source has already completed your research for you. All you’ll need to do is make sure everything is up to date and your task is done.

Secondary sources are often the best place to start your research for several reasons. First, they are organized so as to be easy to find. Once you know how to navigate them, it is often much faster to find information through secondary sources than by searching primary law directly. Second, because they have a broader perspective on the law, they can help you identify issues that you might miss if you try to learn the law through judicial decisions that are concerned with specific fact patterns. Finally, they are written with the goal of educating, and different sources are written for different levels of education and familiarity with the area of law in question. This means that there are secondary sources that are perfect for people who know nothing about the law, sources that are designed to answer questions that come up for practitioners, and sources that provide extremely detailed analysis to assist expert scholars.

Because there are many different kinds of secondary sources, it is important to have an idea of what information each category of source contains, and what kinds of questions they can help you answer. This guide will provide descriptions of these categories, as well as tips on how to find and use them.
Getting Started
If you are completely unfamiliar with an area of law, it is often wise to start with a legal encyclopedia to familiarize yourself with basic terms and concepts before you search further.

Always look up unfamiliar terms in a legal dictionary.  Remember that some terms have special meaning in the law.

When beginning research on a specific legal question, check to see if there is a relevant American Law Report annotation on your question.

To learn about an entire area of the law, or for in depth, authoritative analysis, find a treatise.

If you are researching a legal question that doesn't seem to have a definitive answer, or that has only recently come up, you may be able to find an article in a legal periodical that explores your question in depth.
Encyclopedias, Dictionaries, and Thesauri
Legal encyclopedias, dictionaries and thesauri are similar to their general counterparts. This section will describe how they are used by legal researchers and will familiarize you with specific examples of each.


Legal encyclopedias are used to orient the researcher to unfamiliar areas of the law, and provide fairly general overviews of a large number of legal topics. They are a good place to start because they will provide a context for more specific research, and their broad nature helps ensure the researcher is aware of the scope of the issues being researched.

Encyclopedias should never be cited as sources of the law, but they can be helpful in directing the researcher to primary sources. Most legal encyclopedia articles focus on case law, rather than statutory law, and will include citations to relevant cases. Because of their general nature, encyclopedias are not always the best source for jurisdiction specific primary law sources, but often the citations provided are a good start for finding similar law in a particular jurisdiction.

The two major legal encyclopedias are American Jurisprudence 2d (Am.Jur.) and Corpus Juris Secundum (C.J.S.). Am.Jur. articles are often shorter, and focus on cases the editors determine to be particularly important. C.J.S. articles tend to be longer and more comprehensive. Because C.J.S. is published by Thompson Reuters, it includes West Digest topics and keycite references to help you find related materials in Westlaw and other Thompson Reuters products.
Am. Jur. also publishes topical encyclopedias, which are designed to aid practitioners in more specific areas of the law. These include Am. Jur. Forms, Am. Jur. Proof of Facts, and Am. Jur. Trials. These are designed to provide more technical assistance in areas like trial preparation and finding government and business forms, and are structured less like a traditional encyclopedia.

Some states also have encyclopedias containing information specific to state laws. These encyclopedias vary in quality, and are used less than the general encyclopedias.

General searching advice

Encyclopedias are best used as a starting point, and will often not be specific enough to answer nuanced questions. If you are looking for something similar to an encyclopedia entry on a legal topic that is too specific to be covered in a legal encyclopedia, a good next step is to look for an American Law Reports annotation on your topic.

Once you find an article on your topic, pay attention to the scope notes in the beginning to make sure sure the article covers the information you need, and use the outline to quickly find the specific section or sections that contain your information.  

If you are using an encyclopedia to find primary law, it is very important to make sure that the law cited in your article hasn’t changed by using a service like Shepard’s or Key Cite.


The online editions can be searched by keyword, via the index or by browsing the table of contents.

The table of contents is most useful when you have a general idea of the area you’re researching, because it allows you to go from broad topics to specific articles based on the topic, and it makes it easier to see what else is available under that subject heading that you might want to examine later.

Finding your term in the index is often the fastest way to find an article in an encyclopedia, even online. By searching the index instead of the full text of the dictionary, you will have fewer unrelated results.

Keyword searching can be useful for finding references to obscure terms, or for finding materials when you don’t know what terms they would be listed under in the index.

American Jurisprudence 2d on Westlaw and Lexis Advance
Corpus Juris Secundum on Westlaw

In Print

The print editions are best searched by using the index, which is contained in separate volumes at the end of the series. Find your topic in the index, and then find the volume or volumes that contain the articles you need.  

Be sure to check for updates to your article in the pocket part at the end of the volume. The major encyclopedias are updated quarterly, and checking the pocket part will alert you to new developments in the law.

American Jurisprudence 2d
LAW REFERENCE 2nd floor  KF 154 .A52232

Corpus Juris Secundum
LAW STACKS 2nd floor  KF 154 .C422

Dictionaries and Thesauri

Legal dictionaries define terms as they are used in the law. A legal dictionary will define terms more precisely than a general dictionary, and it will include latin phrases and legal abbreviations. Lawyers use legal dictionaries to look up unfamiliar terms, check to make sure they are using a term correctly, and to persuade a court to interpret a term in a favorable way.

If you’re running a keyword search and the results aren’t what you expected, you can use a dictionary to make sure the term you’re using means what you think it does.

The legal dictionary most commonly used by attorneys and courts is Black’s Law Dictionary. Older dictionaries, such as Bouvier’s Law Dictionary or older editions of Black’s, are sometimes used to trace the historical meaning of a term.  

Garner’s Dictionary of Legal Usage is a combination of a legal dictionary and a style guide, and is primarily devoted to helping legal writers use legal words effectively.  This dictionary is especially useful for drafters of legal documents and students interested in usage.

Another resource that is similar to a dictionary is Words and Phrases, which includes entries on how terms have been defined by courts and statutes, including citations to primary authority. Knowing how terms have been defined in primary law in different contexts can be very helpful, especially if that primary law is binding in your jurisdiction.

Legal thesauri are useful for finding terms for legal concepts and for identifying additional search terms to ensure a comprehensive search. If you are doing a keyword search or attempting to find a subject in an index and your results appear incomplete, a legal thesaurus can help you determine alternate terms to check.

Dictionaries and Thesauri Online

Black’s Law Dictionary is available on Westlaw

Bouvier’s Law Dictionary is available in indexed and digitized form at

The Legal Information Institute’s Wex Legal Dictionary

Dictionaries and Thesauri in Print

Black’s Law Dictionary
LAW REFERENCE 2nd floor  KF 156 .B53 2014

Garner's Dictionary of Legal Usage
LAW REFERENCE 2nd floor  KF 156 .G367 2011

Bouvier’s Law Dictionary
LAW STACKS 2nd floor  KF 156 .B6 1880
Words and Phrases
LAW REFERENCE 2nd floor  KF 156 .W67
Treatises provide an in-depth analysis of an area of law. Some treatises are highly detailed, multi-volume explorations of the law, intended to serve as authoritative reference to practitioners and scholars, while others are designed to help law students and practitioners from other fields learn a subject.
Treatises are often a good first source, particularly if you already know a little about the area you’re searching in and are looking for detailed analysis, or if your goal is to understand a new field well. Treatises generally excel at describing the law clearly and thoroughly.  Most will include citations to the major statutes and judicial decisions in the field, and some have detailed and annotated citations to help you find primary law for more specific legal questions.
Many treatises are updated frequently, with new materials included in pocket parts in print editions, and incorporated into the text of online editions.
Regardless of what kind of treatise you are using or whether you’re using a print or online version, the index or table of contents are generally the best tools to find the specific topic you’re searching for.


Many major treatises can be accessed online through subscription databases. The advantage of using treatises online is that they may be easier to search, and the online editions may receive updates more promptly than the print editions. It is also helpful that updates are incorporated directly into the text, whereas in the print edition, you would need to check for updates in the pocket part at the end of the volume.

On the other hand, some researchers find online editions to be more difficult to read at length or browse through, and many treatises are only available in print.

You can access Westlaw’s collection of treatises by browsing to “Secondary Sources” > “Texts and Treatises”. You can either select the topic area you want to explore, or navigate to Westlaw’s collection of Colorado specific treatises.  

In Lexis Advance, you can find treatise titles by clicking on Browse Source above the search bar, and then narrowing the search by selecting “Secondary Materials,” then “Treatises,” then selecting the practice area and jurisdiction you are researching in. Most of the major treatises will be found in the “Non-jurisdictional” sources, while selecting your state will help you find practice guides and state forms that are relevant for practitioners.

In Print

Treatises for Laypeople

Nolo Press publishes legal books for people who have no experience with the law.

You can browse the Nolo Press books in our collection here or you can search our catalog with the search terms “Nolo” and the topic you wish to know more about, such as “bankruptcy” or “custody”. Make sure you are searching for keywords rather than authors or titles for the best results.

Laypeople may also find treatises written for law students helpful, because while they tend to be more technical than Nolo publications, they are intended to be read by students who start out knowing nothing about the law.

Treatises for Law Students

Law students will generally need treatises that are detailed enough to help them understand the nuances of the areas of law they are studying in their classes, but not so comprehensive that they will be unwieldy to use. There are many treatises that are designed to fit this role, and many of them can be found in our guide to 1L Subject Study Guides.

Sometimes law students will need to research a topic in more depth than is needed for their doctrinal classes, such as when doing research for a legal writing assignment, for clinical work or while working as a summer associate. In these cases, they will find it useful to refer to practitioner or academic treatises.

Treatises for Academics

The treatises most useful to academics are generally the multi-volume, authoritative texts that cover an area of law in exhaustive detail and are frequently updated. The latest edition of a major treatise is often kept on reserve behind the circulation desk. Please feel free to ask a librarian for advice in selecting one.

Treatises for Practitioners

Practitioners will often want to consult state-specific treatises or looseleaf services, since they will most often be looking for laws and rules particular to the jurisdiction in which they practice.

Looseleaf services will generally include information about common or realistic legal problems, and forms that are useful in the field. They are also updated frequently, with pages being replaced and inserted as needed.

Examples include:
The Practitioner's Guide to Colorado Business Organizations

Colorado Workers' Compensation Practice and Procedure

Colorado Family Law and Practice Handbook

Colorado specific materials are kept in shelves across from the reference desk. The fastest way to find what you want is often to come over to the reference area and browse for what you need.
Legal Periodicals
Legal periodicals can be very useful if you are researching an unsettled or obscure area of the law or if you are looking for persuasive authority on a point for which there is not yet a hard rule in your jurisdiction. Legal periodicals are primarily scholarly articles that are published in law reviews, although other periodicals, such as trade magazines, legal newspapers, and commercial journals.

Articles published in law reviews generally contain substantial analysis of narrow legal issues. The issues discussed in law reviews are often in areas where there is still dispute about what the law should be. They are also often focused on theory rather than pragmatic legal questions, although there are journals that are written for practitioners. Because of this focus on novel and hypothetical issues, law review articles are not the best place to start if you are looking to learn about established principles in an area of law.

If you have been unable to find controlling law on your issue, however, articles can be an excellent resource. Law review articles are meticulously sourced, which makes them very useful for finding primary law relevant to the issue they discuss, and if the article is written by a prominent scholar, the analysis and conclusions of an article might be persuasive to a court in deciding how to rule. Because articles are focused on new issues, they can also be excellent resources for familiarizing yourself with issues that are too new to be covered by legal encyclopedia articles or A.L.R. annotations.


There are many good options for finding legal periodicals online.

Google Scholar Unrestricted Resource Some full text available
Provides a simple way to broadly search for scholarly literature. Sources include articles, theses, books, abstracts and court opinions from academic publishers, professional societies, online repositories, universities and other web sites. For quick, free searching, Google Scholar ( can be a good place to start. Google Scholar includes advanced search options such as searching by author or publication, and limiting the data range of the results. Google Scholar is not as comprehensive as some of the other options listed here, and because your results will not be specific to law, it can sometimes be difficult to filter the results you want. Many of the articles returned will be behind paywalls, although if you search while in the law school, you will be able to access those that belong to a database we subscribe to.
Westlaw Unrestricted Resource Resource contains video
Overview of the WestlawNext research system.  Produced by West. To search for legal periodicals on Westlaw Next, browse to Secondary Sources, and then Law Reviews & Journals. You can then either narrow down the periodicals you want to search by geography or topic or search the entire periodical database. Note that narrowing by geography only limits where the article was published, and does not necessarily affect the jurisdition discussed. Coverage in Westlaw varies by publication, but in general, full text is often available for the last two decades, and earlier for some publications.

Lexis Advance Restricted Resource
The latest version of the LexisNexis research system. To search periodicals in Lexis Advance, select Secondary Materials in the content type menu, and then run a search for your search terms. You can then narrow your results to include only Law Reviews and Journals via the filters to the left of the search results. Coverage in Lexis is similar to Westlaw.

HeinOnline Restricted Resource
Full text and images of over 1,000 law journals, each from volume 1 to a few years ago. Other materials include U.S. Reports, the Federal Register, the Code of Federal Regulations, foreign and international resources such as English Reports, U.S. Treaties, world trials, and government documents such as session laws and legislative history. The Law Journal Library at HeinOnline is one of the most comprehensive, and because materials are available as scanned pages from the print edition, the text is extremely reliable. For many older articles, this may be the only place they can be found online.

LegalTRAC (1980 - Date) Restricted Resource
Legal periodical index. Contains major law reviews, legal newspapers, bar association journals and international legal journals going back to 1980. Many articles are available in full text.

SSRN Legal Scholarship Network Unrestricted Resource
The Social Science Research Network includes abstracts and articles that have been submitted for publication  This database is a great place to find upcoming or recent articles. Because many scholars post drafts of their work here before they are officially published, there are many articles here that can't be found through the more traditional databases above. Articles are free to download.

Bepress Digital Commons Unrestricted Resource Some full text available
Allows searching or browsing through peer-reviewed Berkeley Electronic Press journals, plus a wealth of unrestricted working paper series, preprints, monographs, and other content from institutional and subject-matter repositories hosted by bepress.  This is another excellent free resource for searching for legal scholarship. It is not as comprehensive as other databases on this list, but more and more recent scholarship is available here.

In Print

Due to the frequent publishing schedules of legal periodicals, searching for articles in print is increasingly difficult. If possible, I recommend finding citations to articles you would like to read using the online sources above. Please ask a reference librarian if you would like assistance searching for articles online.

If you already have a citation to an article, you can access it in print by searching the library catalog for the publication name (the name of the journal, not the article). The catalog will inform you whether or not we carry the title you are looking for, and whether the library has the specific volume that contains your article. If the volume is in our collection, you can use the call number to locate it.
American Law Reports
American Law Reports (ALR) exist somewhere between encyclopedias and periodicals. ALRs contain in depth articles, called annotations, on narrow issues in the law. Like periodicals, ALRs are published in issues throughout the year. Like an encyclopedia, the annotations are written by commercial publishers rather than academic scholars, and contain descriptions of the law, rather than analysis.

ALR has a very good index, and the titles of annotations tend to be very descriptive, and the second section of each annotation refers readers to related annotations, all of which makes relevant annotations easy to find. Annotations are also updated periodically to reflect changes in the law, so the information is usually fairly current, although it is important to update the citations before using them.

ALR is not as comprehensive as the legal encyclopedias, and there may not be an annotation on the subject you are researching. If there is, however, you will generally be provided with excellent information to guide your research. This is an excellent place to start researching, especially if you know a little about the area of law, but not the specific question you're researching.


Westlaw Unrestricted Resource Resource contains video
Overview of the WestlawNext research system.  Produced by West. You can find ALRs on Westlaw Next by browsing to Secondary Sources, and American Law Reports.

Lexis Advance Restricted Resource
The latest version of the LexisNexis research system. You can find ALR annotations on Lexis Advance by searching in Secondary Materials and narrowing your results by Source to American Law Reports.

In Print

The law library no longer carries an up to date print copy of ALR, so accessing it online is strongly recommended.

When using ALR in print, start with the index, which should lead you to the relevant annotations. Your annotation may have been updated, so check the pocket part at the end of the volume to see if there is any new information on your topic.

American Law Reports 6th
LAW STATE basement  KF 132 .A436 NOT UPDATED
What Next?
For some research questions, finding the appropriate secondary source on a topic is suffiecient. If your goal is to learn the definition of a legal term or understand a basic legal concept, you can consult a dictionary or encyclopedia and successfully answer your question.

If you would like to learn more, you can continue on to use other secondary sources for more depth, or you can read the primary materials cited in the secondary sources.

If you are using secondary sources to find primary law, it is very important to make sure that the cited law is still up to date. This process is called updating, and it can be accomplished with a citator tool like Keycite or Shepards. These tools will inform you if a judicial decision has received negative treatment, or even been overruled since the secondary source was published.

You can also use the primary authority cited to find authority on similar topics in different jurisdictions. Many secondary sources are non-jurisdictional or primarily federal, so this can be an essential step to finding authority that is binding in the relevant jurisdiction.

Further review of the primary sources may reveal new research questions, and it is often useful to cycle back to secondary resources again to answer those questions.  In large and complex legal research, you may return to secondary sources several times to address different issues as they arise.