An information storage/retrieval system stores information to be retrieved in a storage device having a first memory and a second memory. The first memory stores therein main records each containing an index word data, a derivative pattern code and information pieces while the second memory stores therein...http://www.google.de/patents/US4775956?utm_source=gb-gplus-sharePatent US4775956 - Method and system for information storing and retrieval using word stems and derivative pattern codes representing familes of affixes
