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@article{DE_1977_13_2_a3, author = {G. N. Petrovskiǐ}, title = {Admissible changes of time}, journal = {Differencialʹnye uravneni\^a}, pages = {265--270}, publisher = {mathdoc}, volume = {13}, number = {2}, year = {1977}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1977_13_2_a3/} }
G. N. Petrovskiǐ. Admissible changes of time. Differencialʹnye uravneniâ, Tome 13 (1977) no. 2, pp. 265-270. http://geodesic.mathdoc.fr/item/DE_1977_13_2_a3/