000 00285nam a2200121Ia 4500
999 _c21123
_d21123
020 _a8185614660
100 _aJohn Ronayne
245 _aIntroduction to Digital Communications Switching
250 _a2
260 _c1992
_bWHEELER PUBLISHER
_aAllahabad
300 _a238
942 _cBB