@article{DE_1999_35_7_a1,
     author = {S. A. Brykalov},
     title = {A priori estimates and the solvability of problems with nonlinear functional boundary conditions},
     journal = {Differencialʹnye uravneni\^a},
     pages = {874--881},
     year = {1999},
     volume = {35},
     number = {7},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1999_35_7_a1/}
}