%0 Journal Article %A Nieminen, U. J. %T The block plan problem. A graphtheoretic approach %J Kybernetika %D 1973 %P -373 %V 09 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/KYB_1973__9_5_a3/ %G en %F KYB_1973__9_5_a3