00303nam a2200133Ia 45000030006000000080041000060400015000471000022000622450037000842500010001212600009001315460012001400050017001520STCL150530s9999    xx            000 0 und d  aSTCLcSTCL  aStallings William  aData and computer communications  aFifth  c1997  aEnglish20220125160201.0