%0 Journal Article %A B. O. Vasilevskii %T A Sufficient Nonsingularity Condition for a Discrete Finite-Gap One-Energy Two-Dimensional Schr\"odinger Operator on the Quad-Graph %J Funkcionalʹnyj analiz i ego priloženiâ %D 2015 %P 65-70 %V 49 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/FAA_2015_49_3_a5/ %G ru %F FAA_2015_49_3_a5