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@article{DAN_1984_275_5_a3, author = {A. M. Vinogradov and I. S. Krasil'shchik}, title = {On the theory of nonlocal symmetries of nonlinear partial}, journal = {Doklady Akademii Nauk}, pages = {1044--1049}, publisher = {mathdoc}, volume = {275}, number = {5}, year = {1984}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1984_275_5_a3/} }
A. M. Vinogradov; I. S. Krasil'shchik. On the theory of nonlocal symmetries of nonlinear partial. Doklady Akademii Nauk, Tome 275 (1984) no. 5, pp. 1044-1049. http://geodesic.mathdoc.fr/item/DAN_1984_275_5_a3/