@article{DAN_1969_185_4_a1,
     author = {A. V. Bitsadze and A. A. Samarskii},
     title = {Some elementary generalizations of linear elliptic boundary value problems},
     journal = {Doklady Akademii Nauk},
     pages = {739--740},
     publisher = {mathdoc},
     volume = {185},
     number = {4},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1969_185_4_a1/}
}