000 00282nam a2200133Ia 4500
100 _aAlli/Syed R
942 _cBK
654 _adigital
245 _aDigital switching system
260 _bTata Mc Graw hill
_c2002
082 _a621.387
_bALI
300 _a219
546 _aENGLISH
999 _c28928
_d28928