000 00232nam a2200097Ia 4500
008 220201s1970 xx 000 0 eng d
100 _aBISWAS (N N)
245 0 _aPRINCIPLES OF TELEPHONY
260 _bRADIANT BOOK
_c1970
942 _2ddc
999 _c94497
_d94497