000			00327nam a2200133Ia 4500
008			160122s9999 xx 000 0 und d
041			_aEnglish
100			_aWilliam A Say
245			_aUnderstanding Data Communications and Networks
250			_a2nd
260			_bDelhi:vikash pub _c1998
300			_a711p.
650			_aComputer
999			_c989 _d989