%0 Journal Article %A A. Dzhuraev %T On a method of investigating systems of first-order equations in three-dimensional space %J Doklady Akademii Nauk %D 1975 %P 1052-1055 %V 223 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1975_223_5_a3/ %G ru %F DAN_1975_223_5_a3