@article{INTO_2006_110_a2,
     author = {A. V. Dmitruk},
     title = {Nonnegativity criterion for a degenerate quadratic form with two-dimensional control},
     journal = {Itogi nauki i tehniki. Sovremenna\^a matematika i e\"e prilo\v{z}eni\^a. Temati\v{c}eskie obzory},
     pages = {49--75},
     publisher = {mathdoc},
     volume = {110},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTO_2006_110_a2/}
}