00298nam a2200109Ia 4500008004100000022001700041040002500058082001700083100001800100245004200118260002800160240215s9999    xx            000 0 und d  a9-71861369-2  aNORSU-DumcNORSU-Dum  a004.6/H36/C2  a Gilbert Held 0aUnderstanding data communications/3rd  bGlobal Publishingc1998