000			00338nam a2200145Ia 4500
100			_aGilbert Held
020			_a81-7635-319-1
250			_a6th ed
654			_aComputer Science
942			_cBK
245			_aUnderstanding data communications
260			_aTechmedia, New Delhi _cc1999
082			_a001.64404 Hel
300			_axvi,619p
999			_c25943 _d25943