@article{DE_1970_6_8_a5,
     author = {A. Ya. Lepin},
     title = {Necessary and sufficient conditions for the existence of a solution of the two-point boundary value problem for a second order nonlinear ordinary differential equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1384--1388},
     publisher = {mathdoc},
     volume = {6},
     number = {8},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_8_a5/}
}