@article{IVM_2011_8_a8,
     author = {M. Tukhtasinov and U. Ibragimov},
     title = {Sets invariant under an integral constraint on controls},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {69--76},
     year = {2011},
     number = {8},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2011_8_a8/}
}