%0 Journal Article %A B. V. Tischenko %T Existence of solutions of a~system of two ordinary differential equations with a~modular--cubic type nonlinearity %J Teoretičeskaâ i matematičeskaâ fizika %D 2023 %P 318-335 %V 215 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/TMF_2023_215_2_a11/ %G ru %F TMF_2023_215_2_a11