000			00312nam a2200121Ia 4500
100			_aACM
020			_a0-201-07794-9
942			_cBK
245			_aACM turing award lectures the first twenty years
260			_aAddiaon -Wesley pub. company, Massechusetts _c1987
082			_a001.64204 ACM
300			_axviii, 483
999			_c59517 _d59517