000			00387nam a2200181Ia 4500
008			140910s9999 xx 000 0 und d
082			_bHEL - U
100			_aHeld, Gilbert
245			_aUnderstaning Data Communication
250			_a7th
260			_aNew Delhi
260			_bPhi Pub
260			_c2004
300			_a765p
650			_aIT & CS
942			_2DDC
942			_cBook
999			_c21450 _d21450