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@article{IVM_1959_6_a10, author = {N. N. Krasovskii}, title = {On the problem of existence of optimal trajectories}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {81--87}, publisher = {mathdoc}, number = {6}, year = {1959}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1959_6_a10/} }
N. N. Krasovskii. On the problem of existence of optimal trajectories. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 6 (1959), pp. 81-87. http://geodesic.mathdoc.fr/item/IVM_1959_6_a10/