00326nam a2200133Ia 4500008004100000041000800041082001400049100001700063245003800080250001400118260003900132300001400171365000700185240624s9999    xx            000 0 und d  aeng  a004.6 HEL  aHELD GILBERT  aUNDERSTANDING DATA COMMUNICATIONS  a(7th ed.)  c2003aNew DelhibPearson Education  axv, : 765  cRS