TY - JOUR AU - V. A. Pliss TI - On invariant surfaces of a system of two differential equations JO - Doklady Akademii Nauk PY - 1960 SP - 1022 EP - 1024 VL - 131 IS - 5 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DAN_1960_131_5_a8/ LA - ru ID - DAN_1960_131_5_a8 ER -