000 00322 a2200133 4500
020 _a0749260432
082 _a621.382
_bOPE
090 _c13484
_d19845
245 _aBlock 1 Introduction
260 _aNorthampton
_bOpen university
_c1990
_g1990
300 _a32p.
_c29cm
650 _aCommunications engineering
942 _cL
999 _c41815
_d41815