TY  - BOOK
AU  - Vickery,B.C.
TI  - On retrieval system theory / 
U1  - 029.7 VIC  
PY  - 1965///.
CY  - London : 
PB  - Butterworths, 
KW  - Information retrieval
KW  - Information systems
KW  - Libraries - Automation
N1  - Includes index.
ER  -