@article{DE_1974_10_1_a13,
     author = {V. K. Romanko},
     title = {Boundary value problems for a certain class of differential operators},
     journal = {Differencialʹnye uravneni\^a},
     pages = {117--131},
     publisher = {mathdoc},
     volume = {10},
     number = {1},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1974_10_1_a13/}
}