@article{DAN_1964_158_1_a4,
     author = {M. I. Vishik and G. I. \`Eskin},
     title = {General boundary-value problems wtih discontinuous boundary conditions},
     journal = {Doklady Akademii Nauk},
     pages = {25--28},
     publisher = {mathdoc},
     volume = {158},
     number = {1},
     year = {1964},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1964_158_1_a4/}
}