TY  - BOOK
AU  - Kessler, Gary C.
AU  - Southwick, Peter V., Jt. Auth.
TI  - ISDN : concepts, facilities, and services
SN  - 0-07-114430-7
U1  -  004.6 
PY  - 1997///
CY  - New Delhi,India
PB  - McGraw-Hill
KW  - Integrated services digital networks
ER  -