@article{TM_2019_304_a15,
     author = {M. S. Nikol'skii},
     title = {Singular {Sets} of {Extremal} {Controls} in {Optimal} {Control} {Problems}},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {252--256},
     publisher = {mathdoc},
     volume = {304},
     year = {2019},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_2019_304_a15/}
}