A Formal System for Information Retrieval from Files
A generalized file structure is provided
by which the concepts of keyword, index, record, file, directory,
file structure, directory decoding, and record retrieval are defined
and from which some of the frequently used file structures such
as inverted files, index-sequential files, and multilist files are
derived.  Two algorithms which retrieve records from the generalized file 
structure are presented.
CACM February, 1970
Hsiao, D.
