Zelkin Efim Grigorievich

Publications in Math-Net.Ru

1. Transformation of partial differential equations with nonseparable variables into a system of two ordinary differential equations
   
   Differ. Uravn., 27:6 (1991),  1081–1084
2. Systems of two second order differential equations and partial differential equations of elliptic type
   
   Differ. Uravn., 19:4 (1983),  700–703