2 citations to https://www.mathnet.ru/rus/aa1847

1. D. M. Polyakov, “Asymptotics of the Spectrum for a Fourth-Order Differential Operator with a Spectral Parameter in Two Boundary Conditions”, Diff Equat, 61:6 (2025), 755  
2. D. M. Polyakov, “Some Asymptotical Properties for a Fourth-Order Differential Equation with a Spectral Parameter in Three Boundary Conditions”, Lobachevskii J Math, 46:7 (2025), 3182