00255nam a2200121Ia 4500100002100000250000600021654001200027245002400039260003200063082001800095300000800113546001200121  aTokheim/Roger L   a3  adigital  aDigital Electronics  bMcGraw HillaNew Yorkc1990  a621.3815bTOK  a335  aENGLISH