000 00255nam a2200121Ia 4500
100 _aBBrown J
245 _aTelecommunications
250 _a2
260 _c1974
_bE.L.B.S & LONGMAN
_aLondon
300 _axiv+382
700 _aGlazier E V D
942 _cBK
999 _c6815
_d6815