000 00303nam a2200121Ia 4500
008 210219s9999||||xx |||||||||||||| ||und||
082 _a005.8
_bH474U
100 _aHeld, Gilbert
245 0 _aUnderstanding data communications.
260 _aNew Delhi
_bPearson
_c2003
300 _axv,765p
999 _c40151
_d40151