TY  - BOOK
T1  - Private branch exchange systems and applications
A1  - Bush, Stanley E.
A2  - Parsons, Charles R.
LA  - English
PP  - New York
PB  - McGraw-Hill
YR  - 1994
UL  - https://ds.mainlib.upd.edu.ph/Record/UP-99796217602952288
OP  - 193
CN  - TK 6397 B87
SN  - 0070097062
KW  - Telephones : Private branch exchange.
ER  -