000 003060000a22001330004500
245 _aTelecommunications principles and practice
100 _aPerkins, W.T.
250 _a2d ed.
260 _aLondon
_bG.Newnes
_c1961
300 _a384 p., ill.
080 _a621.39
_bP4
041 _aEN
942 _cBK
999 _c52753
_d52753