%0 Journal Article %A T. A. Tushkina %T Calculation of lower bound of schedule length %J Zapiski Nauchnykh Seminarov POMI %D 1983 %P 35-40 %V 124 %I mathdoc %U http://geodesic.mathdoc.fr/item/ZNSL_1983_124_a2/ %G ru %F ZNSL_1983_124_a2