Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1969_5_11_a14, author = {V. S. Mokeichev}, title = {Periodic boundary value problems for certain differential equations}, journal = {Differencialʹnye uravneni\^a}, pages = {2087--2092}, publisher = {mathdoc}, volume = {5}, number = {11}, year = {1969}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1969_5_11_a14/} }
V. S. Mokeichev. Periodic boundary value problems for certain differential equations. Differencialʹnye uravneniâ, Tome 5 (1969) no. 11, pp. 2087-2092. http://geodesic.mathdoc.fr/item/DE_1969_5_11_a14/