000 00000nam a2200000 a 4500
999 _c726
_d57602
001 00000726
008 000000s1998 xx 000 0 eng d
100 1 _aAli, Syed Riffat
245 1 0 _aDigital Switching Systems :
260 _c1998
520 _aEngineering
942 _cBK