1. A method of searching a plurality of documents to be accessed by a plurality of readers or groups of readers, said plurality of documents having been sorted by performing steps of developing a list of interest areas represented by said plurality of readers, developing a hierarchical index of subject matter referred to in said plurality of documents, each entry in said hierarchical index having at least one of an index term and an associated code, assigning a limited number of index terms or associated codes of said hierarchical index to each document of said plurality of documents, assigning at least one of said interest areas to each document of said plurality of documents, and assembling a plurality of hierarchical indices of subject matter for respective interest areas from index terms and associated codes assigned to documents forming a hierarchical database in each of said interest areas, said method comprising steps of searching index terms of one of said plurality of hierarchical indices for index terms corresponding to search terms of a search query, performing a search of said documents in one of said interest areas based on individual or combined index terms that may be assigned to said documents for each index term corresponding to one or more search terms, and logically combining results of each search corresponding to a respective one or more search terms based on assigned index terms.