Browsing in any of these areas may lead to the discovery of valuable material in addition to the specific items listed in this guide. See the volumes titled Library of Congress Subject Headings for a complete list of possible headings and cross references. If you know a specific author or title, you may use that information to access listings in the online catalog also. For searching the contents of journals and other periodicals, it is best to use an indexing or abstracting service, such as Biological Abstracts , before consulting the online catalog.
Many excellent resources are available on the Internet.