000 00331nam a2200121Ia 4500
008 230303s9999 xx 000 0 und d
041 _aeng
082 _a004.6 HEL
100 _aHELD (Gilbert)
245 _aUnderstanding Data Communications from Fundamentals Networking
260 _aChichester
_bJohn Wiley & Sons
365 _cRS
999 _c180986
_d180986