Legal Research Strategy

This guide is intended for graduate level students and staff at the Harvard University who are interested in conducting basic legal research but do not have access to the Westlaw, Lexis Advance or Bloomberg Law databases, which are restricted to Harvard Law School affiliates.

Start your research by reading a legal book or article (often referred to as "secondary sources") before looking at the actual text of the law. Why? Books and articles will help you to identify the primary law (laws, cases and regulations) that applies to topic. Books and articles are also a valuable source of  legal citations to the law. If you are not familiar with the legal topic, recently published books are the best place to start your research if you are looking an overview of current laws. To find a book, search in our catalog, HOLLIS.

Finding a case or statute that appears to be applicable to your topic is not the end of your research.  Primary law is not binding in every jurisdiction.In addition,cases can be overturned in the courts. Statutes and regulations can be repealed or expire. Use up-to-date secondary sources to see if the primary law is still in force.You may also have to conduct a "cite check" in a database like Nexis Uni to determine if a law, statute or regulation is still good law.

Searching for Articles in Law Reviews

General Legal Databases

These expansive databases include a combination of primary and secondary law resources.The terms "primary law" and "primary authority" in  refer to categories of legal texts (statutes and codes, cases, regulations, and treaties) created by legislative bodies, courts, and agencies that taken together are the legal authorities that constitute "the law." In most cases, you should start with secondary sources such as law review articles or books to help you identify important primary law. Search in HOLLIS for books on your legal topic.

Citation Guides

US Law

Case Law

Federal Laws & Regulations

States Laws and Regulations

City/County Codes & Ordinances

There is no easy way to search all municipal codes at the same time. This HKS Library Fast Answer provides detailed instructions for locating municipal ordinances or codes in Nexis Uni. Please note that major metropolitan areas may have town, city and/or county ordinances that apply depending on what part of the metropolitan area you are researching. In some areas, you may have county and city codes that apply.

Search for reputable NGOs and think tanks in your policy area as they may have expert practionerys that monitor changes to state and local code. 

Other free resources that provide access to ordinances/codes are listed below:

https://library.municode.com/ (links to county/local codes where available),


Foreign & International



Foreign & International Law


News & Tracking

Legislative History

Other Guides

Research Guides from other Harvard Libraries

Law Librarians at the Harvard Law Library have authored a large number of specialized legal research guides on topics of interest to members of the Harvard Law School community. They can be viewed at http://guides.library.harvard.edu/law

Some introductory legal research guides are highlighted below:

Non-Harvard State Legal Research Guides

These guides will provide links to their own catalogs or login pages.  Check HOLLIS to see if the resources are available to access the content.