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Substantial Paper Guide: PREEMPTION


As soon as you have settled on a topic and narrowed it down to a manageable claim, you want to run a preemption check to see if someone else has already written a paper that is the same as what you want to write about. You are looking to see if the claim you want to develop has something new to offer—that is, your take on the topic is original, offering new insights.

The steps are simple:  

  1. Look for legal articles on your topic using indexes and databases.
  2. Search for non-legal articles if your topic has an interdisciplinary slant.
  3. Look for articles that have not yet been published—working papers, works in progress.
  4. Search for books, chapters in books.
  5. Set up alerts to stay current on newly-published articles.

Use a variety of sources and a variety of search techniques to ensure you have found all articles related to your topic. It's a good idea to keep a log of sources you check and searches you conducted so you don't inadvertently miss a step or repeat one unnecessarily.

You can also view an excellent CALI tutorial on preemption checking. Log into CALI using your student email. The password is ARIZUAstu. Run a search in the upper right for "preemption." Select the tutorial called "Preemption Checking."


Use the following resources to check for law reviews and journals for papers written on your topic.

Index to Legal Periodicals and Books—indexes hundreds of legal journals, law reviews, yearbooks, institutes, statutes, bar association publications, and university publications; available only in print in the law library, downstairs, periodicals section.

Legal Resource Index (Electronic Companion to Current Law Index)—available on Westlaw; under secondary sources, look to the far right column.

HeinOnline Law Journal Library—available on the law library home page under Quick Links; full-text coverage of over 2,200 law and law-related periodicals, most back to inception.

Lexis Advance and Westlaw—both databases contain the full text of law reviews and journals; however, coverage is more limited than HeinOnline; both are under secondary sources tab.

Academic Search Complete—if your topic is interdisciplinary in nature, you should check non-legal publications; available from the main library database collection.


Use the following sites to search for working papers on your topic.

SSRN Legal Scholarship Network—contains working papers, papers accepted for publication, and published articles. Good for discovering popular articles related to particular topics and what is upcoming.

bepress Legal Repository—working papers and published articles by institution and searchable by subject area.


Many scholarly books consist of essays or articles by different authors that are compiled by an editor. Use the sources below to check to see if there has been a book or a chapter from a book written on your topic.

WorldCat—a database of library collections from around the world; often entries will include a table of contents so a keyword search will look for titles of books, as well as chapters; available through the main library.

Library Catalog—search for locally available materials using the library catalog; access from the law library home page under Quick Links; use either the discovery-layer catalog Summon or the OPAC catalog.


You want to keep up with any changes that might occur related to your topic. One way to do this is to set up alerts.

Current Index to Legal Periodicals (CILP)—available through Westlaw; under secondary sources tab, look to far right column; provides access to contents of more than 550 legal periodicals for the last eight weeks.

Sign up for regular emails from blogs and news websites on your topic.

Westlaw offers several alert options. To set up an alert, click on the Alerts link at the top right of the screen. For more details, view the Alerts Guide and Practitioner's Insights Guide.

Lexis Advance offers alert options. To set up an alert, click on the More drop-down box and select Alerts. For more details, view the Using Lexis Advance Alerts guide.