2 citations to https://www.mathnet.ru/rus/tmf8977

1. Anatoly G. Nikitin, Integrability, Supersymmetry and Coherent States, 2019, 133  
2. F. Correa, V. Jakubsky, “Confluent Crum–Darboux transformations in Dirac Hamiltonians with $PT$-symmetric Bragg gratings”, Phys. Rev. A, 95:3 (2017), 033807