000 00249nam a2200121Ia 4500
020 _a9781259004605
082 _a621.382
100 _aSINGH R.P
245 _aCOMMUICATION SYSTEMS
250 _a3 RD
260 _aNEW DELHI
_b TMH
_c2012
942 _cBK
999 _c6686
_d6686