@article{DE_1982_18_2_a1,
     author = {A. I. Vahabov},
     title = {On the multiple completeness of eigenfunctions of a type of ordinary differential pencil},
     journal = {Differencialʹnye uravneni\^a},
     pages = {194--197},
     publisher = {mathdoc},
     volume = {18},
     number = {2},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1982_18_2_a1/}
}