TY - JOUR AU - M. N. Yakovlev TI - Nonnegative solutions of systems of nonlinear (in particular, difference) equations JO - Trudy Matematicheskogo Instituta imeni V.A. Steklova PY - 1968 SP - 111 EP - 116 VL - 96 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TM_1968_96_a10/ LA - ru ID - TM_1968_96_a10 ER -