@article{DE_1991_27_12_a15,
     author = {V. K. Romanko},
     title = {Boundary value problems for degenerate systems of equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2138--2147},
     publisher = {mathdoc},
     volume = {27},
     number = {12},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1991_27_12_a15/}
}