2 citations to https://www.mathnet.ru/rus/tmf645

1. Obukhov V., “Separation of Variables in Hamilton-Jacobi and Klein-Gordon-Fock Equations For a Charged Test Particle in the Stackel Spaces of Type (1.1)”, Int. J. Geom. Methods Mod. Phys., 18:3 (2021), 2150036    
2. Obukhov V., “Separation of Variables in Hamilton-Jacobi Equation For a Charged Test Particle in the Stackel Spaces of Type (2.1)”, Int. J. Geom. Methods Mod. Phys., 17:14 (2020), 2050186