000 00296nam a2200121Ia 4500
008 210219s9999||||xx |||||||||||||| ||und||
082 _a621.38104
100 _aBiswas N N
245 0 _aPrinciples of telephony
_cBiswas N N
260 _aBanglore
_bRadient books
_c1992
300 _a138
999 _c1282
_d1282