1
Clark IV William A, Salmond Kent A, Stafford Thomas S: Method and means for generating compressed keys. International Business Machines Corporation, July 13, 1971: US3593309 (18 worldwide citation)

Electronically compressing a sorted sequence of uncompressed keys, each having an associated pointer address for accessing the information represented by the key. Compression is by electronic transfer of the remaining part of any key after removing some or all of (1) high-order 'factored' bytes, and ...


2
Method and means for generating compressed keys. Ibm, July 5, 1972: GB1280483-A

1280483 Information retrieval; calculating INTERNATIONAL BUSINESS MACHINES CORP 30 Dec 1969 [3 Jan 1969] 63202/69 Headings G4A and G4C] Compressed keys, for information retrieval, are generated from a source index of uncompressed keys by accessing each key and its next key in a sorted sequence to ob ...