2 citations to https://www.mathnet.ru/eng/tm4112

1. I. Yu. Polekhin, “The existence proof for forced oscillations by adding dissipative forces in the example of a spherical pendulum”, Theoret. and Math. Phys., 211:2 (2022), 692–700          
2. I. P. Popov, “Varieties of mechanical powers”, J. Mach. Manuf. Reliab., 51:8 (2022), 746