@article{DE_1987_23_8_a8,
     author = {\`E. M. Saak},
     title = {The {Riemann} problem for nonselfadjoint elliptic differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1360--1366},
     publisher = {mathdoc},
     volume = {23},
     number = {8},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1987_23_8_a8/}
}