Document retrieval system; method of document retrieval; and search server

摘要

A system and method for searching both keyword-search-type databases and associative-document-search-type databases with a single search query. All or a part of the search results returned from an initial search may be used to construct a query for a subsequent search in the same or a different database. A search server may provide results to a document retrieval terminal in a merged form with document identifiers from several different types of databases. The search server may prompt a user to modify and confirm a constructed Boolean search to make sure that the search is syntactically correct for a given keyword-type-search database.