000			00309nam a22001337a 4500
999			_c2893 _d2893
020			_a9780672309342
082			_a006.4
100			_aGilbert Held
245			_aUnderstanding Data Communications
250			_aFifth
260			_aUnited States of America _bSams Publishing _c1996
300			_a504
942			_cBK