@article{DAN_1991_317_5_a7,
     author = {M. S. Salakhitdinov and A. K. Urinov},
     title = {Problems of {Bitsadze{\textendash}Samarskii} type for an equation of mixed type},
     journal = {Doklady Akademii Nauk},
     pages = {1058--1061},
     year = {1991},
     volume = {317},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_317_5_a7/}
}