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@article{DE_1987_23_10_a12, author = {M. D. Kovalenko}, title = {Biorthogonal expansions in eigenfunctions. {I}}, journal = {Differencialʹnye uravneni\^a}, pages = {1764--1772}, publisher = {mathdoc}, volume = {23}, number = {10}, year = {1987}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1987_23_10_a12/} }
M. D. Kovalenko. Biorthogonal expansions in eigenfunctions. I. Differencialʹnye uravneniâ, Tome 23 (1987) no. 10, pp. 1764-1772. http://geodesic.mathdoc.fr/item/DE_1987_23_10_a12/