000 003240000a22001330004500
245 _aTelephony and telegraphy : an introduction to instruments and exchanges
100 _aSmith, S.F.
250 _a2d ed.
260 _aLondon
_bO.U.P.
_c1974
300 _a282 p.
080 _a621.39
_bS6
041 _aEN
942 _cBK
999 _c103167
_d103167