2 citations to https://www.mathnet.ru/rus/tmf9541

1. V Chistyakov, “On quantum analogue of instable oscillating states of an inverted oscillator in external poly-harmonic field”, J. Phys.: Conf. Ser., 2103:1 (2021), 012077  
2. P. A. Golovinski, “Dynamics of driven brownian inverted oscillator”, Phys. Lett. A, 384:10 (2020), 126203