Subject matter research services are often called "looseleaf" services. Many are actually published in looseleaf binders so the publisher is able to update individual pages or sections as necessary.
Subject matter research services are also available in many other formats, including bound print volumes, CD-ROMs, and internet databases.
A subject matter research service may contain some or all of the following types of information:
Some areas for which subject matter services are available include environmental law, tax, bankruptcy, government contracts, intellectual property, employment and labor law, and securities law.
Some of the best known publishers of subject matter services are:
Both Lexis and Westlaw have databases devoted to subject areas of the law. These databases allow you to search cases, statutes, regulations, secondary sources, and other materials in a subject area, instead of by jurisdiction. You could search all jurisdictions in that subject area, or you could choose to search only materials for an individual state.