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@article{DE_1977_13_3_a4, author = {F. Clarke}, title = {Extremal arcs and extended {Hamiltonian} systems}, journal = {Differencialʹnye uravneni\^a}, pages = {427--442}, publisher = {mathdoc}, volume = {13}, number = {3}, year = {1977}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1977_13_3_a4/} }
F. Clarke. Extremal arcs and extended Hamiltonian systems. Differencialʹnye uravneniâ, Tome 13 (1977) no. 3, pp. 427-442. http://geodesic.mathdoc.fr/item/DE_1977_13_3_a4/