ROMANOV, S. S. Piecewise-maximum closed Geodesic trajectories on bounded Toroidal manifolds. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 56, n. 8, p. 1139–1142, 2004. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3829. Acesso em: 5 dec. 2025.