%0 Journal Article %A S. S. Ryshkov %T On the problem of determining perfect quadratic forms of several variables %J Informatics and Automation %D 1976 %P 215-239 %V 142 %I mathdoc %U http://geodesic.mathdoc.fr/item/TRSPY_1976_142_a17/ %G ru %F TRSPY_1976_142_a17