DYMARSKII, Ya. M. Manifolds of Eigenfunctions and Potentials of a Family of Periodic Sturm–Liouville Problems. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 8, p. 1042–1052, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4145. Acesso em: 5 dec. 2025.