%0 Journal Article %A P. A. Frolov %T Topological structure of normally solvable first boundary-value problems in the plane %J Funkcionalʹnyj analiz i ego priloženiâ %D 1979 %P 60-70 %V 13 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/FAA_1979_13_3_a6/ %G ru %F FAA_1979_13_3_a6