The US National Agricultural Library, the largest agricultural library in the world, has a Web gateway to its mammoth AGRICOLA (AGRICultural OnLine Access) database. AGRICOLA "is a machine-readable database of bibliographic records created by the National Agricultural Library and its cooperators. Production of these records in electronic form began in 1970, but the database covers materials dating from the 16th century to the present. The records describe publications and resources encompassing all aspects of agriculture and allied disciplines, including plant and animal sciences, forestry, entomology, soil and water resources, agricultural economics, agricultural engineering, agricultural products, alternative farming practices, and food and nutrition." The Web interface is divided into two sections at this time, an online public access book catalog and a "journal article citation index." The book catalog contains bibliographic records produced since 1970, while the journal section contains records produced since 1985. Searching is available on six variables for each section, and several of the indexes are browseable, for ease of use.