000			00580nam a2200205Ia 4500
008			161214s9999 xx 000 0 und d
020			_a8176353191 _c(pbk)
082			_223 _a621.3981 _bHEL
100			_aHeld, Gilbert
245		0	_aUnderstanding Data Communications
250			_a6th ed.
260			_aNew Delhi: _bTechmedia, _c1999
300			_a619 p.; _bIllus. Index.: _c24 cm.
650			_aData Communications
650			_aDigital Transmission
650			_aFiber-Optics
650			_aMessages and Transmission Channels
650			_aTerminal Devices
942			_2ddc _cBK
999			_c8500 _d8500