000 00279nam a2200121Ia 4500
008 220201s1969 xx 000 0 eng d
082 _a621.381
100 _aGayford, ML
245 0 _aModern relay techniques
260 _bLondon: newsness
_c1969
300 _a149
942 _2ddc
999 _c76722
_d76722