00313nam a2200133Ia 4500008004100000020001800041041000800059082001400067100002300081245003300104250001600137260001800153300000800171211209s2021    xx            000 0 und d  a9789352866601  aeng  a005.8 STA  aSTALLINGS, WILLIAM  aNETWORK SECURITY ESSENTIALS   a6TH EDN ed.  bPEARSONc2021  a461