For more information, see its online help . It searches over 150 million web pages and 5,400 full-text sources of magazines, journals, books, newspapers, pamphlets, and newswires. Its power search is especially useful. Clicking on one will focus your search. See its quick reference card or user guide from UC Berkeley.
Web directories simultaneously.
Meta-search engines are particularly useful when searching for obscure items. MetaCrawler searches a number of search engines simultaneously, including Lycos, Infoseek, WebCrawler, Excite, AltaVista, Thunderstone, The Mining Co., Looksmart, and Yahoo. MetaCrawler organizes the results into a uniform format, ranks them by relevance, and returns them to the user. Dogpile searches over ten different search engines at the same time. 2.1 Databases Europe's Network of Patent Databases Facsimile images of patent documents from 20 countries from 1920 onwards are available in PDF format.