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Northern Illinois University
College of Law
David C. Shapiro Memorial Law Library

Secondary Sources: Treatises

This Guide will provide a more in-depth explanation about finding, identifying, and using Treatises in legal research


Editors - a person or group of people who curate the content of a treatise into a coherent and organized resource.

Authors - person or group of people who have written the content of the treatise.  While some author(s) are responsible for the entirety of a treatise, in some instances there may be many individual authors responsible for sections and/or chapters of the treatise, which is then organized by the editors.

Edition - over time, enough new content has emerged that the treatise will be updated into a new edition.  Please Note: this is different from pocket part or looseleaf updates; this is an entirely new printing, not just printing new material.

Publisher - usually a company which has printed the written materials into a print edition or digitized the materials into an online format.

Copyright Year - this is the date the full treatise was published in it's entirety

Update Year - when a treatise is updated via looseleaf inserts, pocketparts, or annual supplement, the treatise has been officially updated, meaning that even the parts unchanged are "current through" the update year.

Volume - some treatises are single volume, but many are multi-volume.  It is important to identify how many volumes are available to ensure you are not missing any information.

Looseleaf Treatise - some treatises are so large, they are published in three ring binders so that the pages may be removed easily.  This is that any update pages can be added without disturbing the rest of the unchanged materials.

Pocket Part - bound treatises may be updated with a pocketpart, which is a multi-page pamphlet inserted into the "pocket" in the back of the book.  This pocket part has all the updated material in the treatise so that the full treatise does not require to be reprinted every year.

Ways to Identify a Treatise from Other Resources

Treatises will often times refer to themselves as Treatises.  However, other times they refer to themselves in other ways, while still being Treatises.  These are a few of the synonymous terms used in place of "Treatise."

The Author's Name is in the Title - often Treatises will be identifyable since the author's name will be included in the title.  Examples include Nimmer on Copyright and Gitlin on Divorce.  When you see these types of titles, this usually means it is a Treatise

Look at "About" Section - in the "About" section the Treatise will often refer to itself as "...this Treatise will...."  Sometimes, the term Treatise will be replaced by synonmyous terms such sas Text, Material, or Book.


There are many resources which fit into the standard definition of Treatise but which are not considered Treatises in a general sense, or are considered something more or less than a standard Treatise.  This list of resources are secondary sources which can be easily mistaken for Treatises based on the defintion.

Hornbooks and Concise Hornbooks: commonly referred to as "student treatise" which focus on one topic, but in a more rudimentary or introductory way.

Casebooks: another type of student treatise, but which focuses extensively on case law and provides context to the case law precedents as opposed to using the cases to explain the overall topic.

Handbooks: often meant for practitioners who need a "desk reference" for particular legal topics.  Useful for students as well, but more focused on practical law than traditional treatises.

Formbooks: similar to Handbooks, another desk reference which provides boilerplate terms, clauses, or documents that practicing attorneys can use for their own clients' needs.

Continuing Legal Education (CLE): these materials often focus on a particular issue within a particular topic to focus in an attorney's knowledg for practice considerations.  The form varies by jurisdiction; Illinois' CLE materials (IICLE) are a combination treatise, formbook, and handbook with varying degrees of focus depending on the subject.  

Treaties vs. Treatises 

A Treaty is an agreement between nations which is formally signed, ratified, or otherwise adhered to between the participating countries.

Treatise is a secondary source which is highly focused on one legal topic and meant to provide more clarity and context to that topic.

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