00300nam a2200133Ia 45000030006000000080041000060400015000471000015000622450041000772500010001182600009001285460012001370050017001490STCL150530s9999    xx            000 0 und d  aSTCLcSTCL  aCarr, J.J.  aElements of electronic communication  aFirst  c1978  aEnglish20220125170210.0