@article{DE_1985_21_3_a5,
     author = {N. A. Kurzhanskaya},
     title = {Optimal control of a pencil of trajectories of a system with sub-definite parameters},
     journal = {Differencialʹnye uravneni\^a},
     pages = {404--410},
     year = {1985},
     volume = {21},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1985_21_3_a5/}
}