2 citations to https://www.mathnet.ru/rus/mmj184

1. Stoyanova Ts., “Stokes Matrices of a Reducible Double Confluent Heun Equation Via Monodromy Matrices of a Reducible General Huen Equation With Symmetric Finite Singularities”, J. Dyn. Control Syst., 28:1 (2022), 207–245        
2. Stoyanova Ts., “Zero Level Perturbation of a Certain Third-Order Linear Solvable Ode With An Irregular Singularity At the Origin of Poincar, Rank 1”, J. Dyn. Control Syst., 24:4 (2018), 511–539