%0 Journal Article %A M. N. Yakovlev %T Nonnegative solutions of systems of nonlinear (in particular, difference) equations %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1968 %P 111-116 %V 96 %I mathdoc %U http://geodesic.mathdoc.fr/item/TM_1968_96_a10/ %G ru %F TM_1968_96_a10