2 citations to https://www.mathnet.ru/rus/zvmmf976

1. Assanova A.T., Uteshova R.E., “A Singular Boundary Value Problem For Evolution Equations of Hyperbolic Type”, Chaos Solitons Fractals, 143 (2021), 110517        
2. Dzhumabaev D.S., Temesheva S.M., “Bounder Solution on a Strip to a System of Nonlinear Hyperbolic Equations With Mixed Derivatives”, Bull. Karaganda Univ-Math., 84:4 (2016), 35–45