000 00285nam a2200121Ia 4500
020 _a8185614660
100 _aJohn Ronayne
245 _aIntroduction to digital communications switching
250 _a2
260 _c1992
_bWHEELER PUBLISHING
_aAllahabad
300 _a236
942 _cBK
999 _c20053
_d20053