@article{DE_1988_24_3_a18,
     author = {A. I. Perov and E. G. Glushko and I. G. Tyuleneva},
     title = {Eigenvalues and eigenfunctions of an integro-differential operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {516--519},
     publisher = {mathdoc},
     volume = {24},
     number = {3},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1988_24_3_a18/}
}