%0 Journal Article %A S. S. Ryshkov %T On V.\,A.~Borovikov's paper: A~topological problem Bearing on certain issues of quantum electrodynamics %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1960 %V 15 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/RM_1960_15_3_a23/ %G ru %F RM_1960_15_3_a23