@article{DE_1980_16_11_a3,
     author = {A. B. Budak},
     title = {Some properties of eigenfunctions of a fourth-order differential operator with discontinuous coefficients},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1943--1955},
     publisher = {mathdoc},
     volume = {16},
     number = {11},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1980_16_11_a3/}
}