V. V. Vedyushkina, A. V. Zaitseva, “Topology of the Liouville foliation for an integrable billiard bounded by parabolas and having a gravitational potential”, Vestnik Moskov. Univ. Ser. 1. Mat. Mekh., 2025, no. 3, 22–31; Moscow University Mathematics Bulletin, 80:3 (2025), 173–183
