Secondary sources are works which are not themselves the law, but which discuss or analyze legal doctrine. They include legal dictionaries, encyclopedias, treatises, restatements of the law and academic journals known as law reviews. They are written with the goal to make primary sources more accessible and can be a good starting place for research, but are rarely used in court documents like briefs. They will provide you with background information and context, as well as cross-reference primary sources. It is important to recognize source types and understand where to find them, but you do not need to search through each type for every project.
The law developed its own language, in which Latin words and phrases are still prevalent and everyday words have specialized meanings in legal writing. Legal dictionaries will help you understand the terms used in your legal issue and the terms of art - those words with a specific meaning in a particular field.
Law dictionaries are in the reference collection of Snowden Library, on the first floor. If you have trouble finding them, don't hesitate to ask for help! Here are a few suggestions to get you started:
| Black's Law Dictionary | Call #: Ref. KF156 .B53 2009 |
| Burton's Legal Thesaurus | Call #: Ref. KF156 .B856 1998 |
| Oran's Dictionary of the Law | Call #: Ref. KF156 .O69 2008 |
| The Supreme Court A to Z | Call #: Ref. KF8742 .A35 S8 2007 |
The Unified Judicial System of Pennsylvania website also provides a free online law dictionary:
Legal encyclopedias cover broad areas of the law and include articles on legal doctrines and terminology, major court decisions, government agencies, and influential jurists, etc. Legal encyclopedias are a great starting point for preliminary research and for case-finding, but they are slow to reflect changes in the law and cover emerging trends.
Print copies of encyclopedias are in the reference collection of Snowden Library, on the first floor. Some encyclopedias are available through our digital collections. If you have trouble finding them, don't hesitate to ask for help! Here are a few recommendations to get you started:
| The Oxford Companion to American Law | Ref. KF154 .O96 2022 |
| West's Encyclopedia of American Law | Ref. KF154 .W47 2004 v.1-v.13 |
| Essential Supreme Court Decisions | Ref. KF4547 .4 .V55 2010 |
| Encyclopedia of the American Constitution | Ref. KF45448 .E53 2000 |
| Gale Encyclopedia of American Law | Available via Gale Virtual Reference Library |
Oyez is the unofficial archive of the Supreme Court of the United States. It is the most complete and authoritative source for all of the Court’s audio from 1955-present. Use this website to find case summaries, detailed information on justices and court audio.
Academic journals in the field of law are called law reviews and are generally edited by law students as opposed to established scholars. They are useful because the summarize an area of the law and contain footnotes that can lead you to primary sources. They also cover trends and changes to the legal doctrine, as well as discuss recent cases. Law reviews articles often contain the perspective of their author on the topics covered, and thus are not as neutral as other sources.
This database gives you access to the Law Journal Library, a collection of scholarly journals which include law reviews. In HeinOnline, you can filter by Databases and select the "Law Journal Library", then enter your keywords in the search bar or search by titles.
This database also allows you to search through law reviews. You can filter by Content Type, select "Legal" and then choose "Law Reviews and Journals". You can also use the Guided Search and select "Law Reviews".