A system for querying disparate, heterogeneous data sources over a network, where at least some of the data sources are World Wide Web pages or other semi-structured data sources, includes a query converter, a command transmitter, and a data retriever. The query converter produces, from at least a portion...http://www.google.com/patents/US5913214?utm_source=gb-gplus-sharePatent US5913214 - Data extraction from world wide web pages
