%0 Journal Article %A Kečkemétyová, Mária %T On the existence of a solution for nonlinear operator equations in Fréchet spaces %J Mathematica slovaca %D 1992 %P 43-54 %V 42 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/MASLO_1992__42_1_a3/ %G en %F MASLO_1992__42_1_a3