@article{DE_1989_25_3_a25,
     author = {A. K. Pulatov},
     title = {A {Bitsadze-Samarskiǐ} problem},
     journal = {Differencialʹnye uravneni\^a},
     pages = {537--540},
     year = {1989},
     volume = {25},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1989_25_3_a25/}
}