000 00351nam a2200145Ia 4500
008 240624s9999 xx 000 0 und d
041 _aeng
082 _a004.6 HEL
100 _aHELD GILBERT
245 _aUNDERSTANDING DATA COMMUNICATIONS
250 _a(7th ed.)
260 _c2003
_aNew Delhi
_bPearson Education
300 _axv, : 765
365 _cRS
999 _c853
_d853