The materials used for legal research are generally divided into two broad categories: primary sources and secondary sources. Primary sources are laws, orders, decisions, or regulations issued by a governmental entity or official, such as a court, legislature, or executive agency; the President; or a state governor. Secondary sources offer analysis, commentary, or a restatement of primary law and are used to help locate and explain primary sources of law. Secondary sources may influence a legal decision but do not have the controlling or binding authority of primary sources.
The Library has an extensive collection of legal treatises and other commentaries. To locate items of interest to you, start with an online catalog search, http://catalog.loc.gov/. If you have any questions, consult a reference librarian at the Law Library Reading Room Reference Desk by calling (202) 707-5080 or by using Ask a Librarian.
Legal dictionaries provide definitions of words in their legal sense or use. These publications provide a short definition of foreign and Latin legal words and phrases, refer to cases and other legal sources for authority, and may give examples of word usage in various legal situations. They also include tables defining legal abbreviations and acronyms. Black’s Law Dictionary is the leading legal dictionary in the US: Black’s Law Dictionary 9th ed., Call No. KF156 .B53 2009 (10th ed. expected in 2014/2015).
Words & Phrases
Words & Phrases is a multivolume research tool, similar to a legal dictionary in that it includes legal definitions of words. However, Words & Phrases also includes multiple entries indicating how the term or the word has been defined by the courts: Words and Phrases, Call No. KF156 .W6712 (kept current with pocket parts and supplements).
Legal Encyclopedias offer broad and general commentary on a full range of federal and state law. These are useful as a starting point for researching unfamiliar areas of law. Most of the articles in encyclopedias focus on case law and do not contain extensive citations to statutes or other secondary sources.
The two major legal encyclopedias on US law are the following:
- American Jurisprudence (Am. Jur.) 2d, Call No. KF154 .A42 (kept current with pocket parts & supplements); available onsite only in LexisNexis Library Express database, http://eresources.loc.gov/record=e1000623~S9.
- Corpus Juris Secundum (CJS), Call No. KF154 .C56 (kept current with pocket parts & supplements)
Many (but not all) states have a legal encyclopedia focusing exclusively on the laws of that state. The following are some examples:
Annotated Law Reports
Annotated law reports provide essays that analyze and discuss particular points of law. They focus on narrow legal issues rather than general points of law. The articles analyze and describe cases from every jurisdiction that have taken a position on the topic covered. Along with critical case citations, the articles provide references to statutes, digests, texts, treatises, law reviews, and legal encyclopedias. The American Law Reports (ALR) series by Thomson/West is the most comprehensive set of annotated law reports. The series currently comprises seven series: ALR 1st, ALR 2nd, ALR 3rd, ALR 4th, ALR 5th, ALR 6th, and ALR Federal and ALR Federal 2d. Locate articles of interest via the print Index volumes. American Law Reports, Call No. KF132 .A56 and American Law Reports Federal, Call No. KF132 .A47.
Legal periodicals are very helpful in locating cases and statutes in a particular subject area. Periodicals are also an excellent method of locating current information. Subjects that are new or too specialized to be covered in books can often be found in periodicals. Articles in periodicals describe, analyze, and comment on the current state of the law. There are numerous types of legal periodicals available, including law school journals and law reviews, bar association journals, legal newspapers, and legal newsletters.
Legal Treatises, Hornbooks and Nutshells
Legal treatises are publications that present a highly-organized and detailed explanation of a specific area of law (for example, contract, tort, criminal, or property law). Treatises are published as single-volume or multivolume sets. Most treatises are updated by the use of supplements or pocket parts. Following are selected examples of treatises:
- Farnsworth on Contracts (3rd ed.), Call No. KF801 .F367 2004
- Federal Practice and Procedure, Wright & Miller, Call No. KF8840 .W68
- The New Wigmore: A Treatise on Evidence, Call No. KF8935 .N49 2010
Hornbooks are a type of treatise that provide the basics of a given legal topic. They are usually one-volume publications related to subjects covered in law school courses. The following publication is an example of a hornbook: Criminal Law, Call No. KF9219 .L38 2010.
The Thomson/West multivolume Nutshell Series provides an overview of substantive areas of law, legal and legislative processes, legal research and writing, and other law-related matters. The depth of analysis and explanation in a Nutshell is considerably more concise as compared to a treatise or hornbook, but Nutshells serve as a good introduction to an unfamiliar area of law. The following is an example of a Nutshell: Civil Procedure in a Nutshell (7th ed.), Call No. KF8841 .K36 2013.
Restatements of the Law organize the common law of the United States in a distinctive format that includes the text of legal provisions, official commentary, illustrations, and notes. They are written by the American Law Institute (ALI), which is a legal organization composed of noted professors, judges, and lawyers. Restatements are divided broadly into chapters and subdivided into titles and then into sections. Each section begins with a restatement of the law, followed by hypothetical illustrations. Restatements often influence court decisions but are not binding on the courts in and of themselves. ALI has completed Restatements in over fifteen subject areas. The following are selected examples of Restatements of the Law:
- Restatement of the Law of Agency (3rd ed.), Call No. KF1345 .A764 2006
- Restatement of Conflict of Laws (2nd ed.), Call No. KF411 .R47, 1971
- Restatement of Contracts (2nd ed.), Call No. KF801 .R47 1981
- Restatement of the Foreign Relations Law of the United States (rev. ed.), Call No. KF4651 .R47 1987
- Restatement of Judgments (2nd ed.), Call No. KF8990 .R48, 1982
- Restatement of the Law Governing Lawyers, Call No. KF300 .R469 2000
- Restatement of the Law Restitution and Unjust Enrichment (3rd ed.), Call No. KF1244 .R473 2011
- Restatement of the Law of Torts (3rd ed.), Call No. KF1257 .R467 2010
Loose-leaf publications are useful tools for keeping current with rapidly changing laws, regulations, and rulings. These publications generally include regulation-intensive subjects such as banking, tax, Medicare, or securities. All of these areas of law and corresponding regulations change frequently; the loose-leaf format allows current information to be easily added to existing materials by inserting new pages and/or by removing some of the existing pages. The followings are examples of loose-leaf services:
Legal directories are locators for legal and government information. A variety of resources provide information about attorneys, law firms, legal experts, professors, government officers, corporate legal departments, legal aid organizations, and elected officials. For example, the Federal Regulatory Directory is a comprehensive guide to federal regulatory agencies. It includes citations to laws under which agencies derive their regulatory responsibilities. The United States Government Manual is a directory of federal agencies. Entries include a description of responsibilities of the agency, contacts, and references to the legislation that established the agency. The most popular legal directory is the Martindale-Hubbell Law Directory, which provides a listing of attorneys and law firms by state and other countries. The website allows for searches by lawyer, practice area, or geographic location.
Some directories include information about lawyers practicing in a specific area of law and/or in specific jurisdictions. These are called specialty directories. The following are examples of such publications:
For further assistance consult a reference librarian at the Law Library Reading Room Reference Desk by calling (202) 707-5080 or by using Ask a Librarian.
Last Updated: 06/09/2015