000			00352nam a2200169Ia 4500
008			240220s9999 xx 000 0 und d
041			_aENG
100			_aBiswas N. N.
245		0	_aPrinciples of telephony.
260			_aNULL
260			_bRadiant Books.
260			_c1991
300			_a138p.
365			_b25
650			_aETC
942			_cDBK
999			_c22345 _d22345