%0 Journal Article %A G. G. Ivanov %T Symmetries, conservation laws, and exact solutions in nonlinear sigma models %J Teoretičeskaâ i matematičeskaâ fizika %D 1983 %P 45-54 %V 57 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/TMF_1983_57_1_a5/ %G ru %F TMF_1983_57_1_a5