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@article{DAN_1961_136_6_a9, author = {B. V. Shabat}, title = {On the notion of derivative system according to {M.\,A.~Lavrentʹev}}, journal = {Doklady Akademii Nauk}, pages = {1298--1301}, publisher = {mathdoc}, volume = {136}, number = {6}, year = {1961}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1961_136_6_a9/} }
B. V. Shabat. On the notion of derivative system according to M.\,A.~Lavrentʹev. Doklady Akademii Nauk, Tome 136 (1961) no. 6, pp. 1298-1301. http://geodesic.mathdoc.fr/item/DAN_1961_136_6_a9/