@article{DAN_1981_257_1_a1,
     author = {A. I. Vahabov},
     title = {On the question of completeness of the system of eigenfunctions of a nonregular ordinary differential pencil},
     journal = {Doklady Akademii Nauk},
     pages = {15--18},
     publisher = {mathdoc},
     volume = {257},
     number = {1},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1981_257_1_a1/}
}