Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DE_1971_7_2_a23, author = {V. G. Hryptun}, title = {The eigenfunction expansion of a certain linear operator}, journal = {Differencialʹnye uravneni\^a}, pages = {373--375}, publisher = {mathdoc}, volume = {7}, number = {2}, year = {1971}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1971_7_2_a23/} }
V. G. Hryptun. The eigenfunction expansion of a certain linear operator. Differencialʹnye uravneniâ, Tome 7 (1971) no. 2, pp. 373-375. http://geodesic.mathdoc.fr/item/DE_1971_7_2_a23/