%0 Journal Article %A A. K. Prikarpatskii %A N. N. Bogolyubov %T A bilocal periodic problem for Sturm--Liouville and Dirac differential operators, and some applications in the theory of nonlinear dynamical systems %J Doklady Akademii Nauk %D 1990 %P 29-32 %V 310 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1990_310_1_a5/ %G ru %F DAN_1990_310_1_a5