BAŞKAYA, E.; COŞKUN, H.; KABATAŞ, A. Instability intervals for Hill’s equation with symmetric single-well potential. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 71, n. 6, p. 858–864, 2019. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1481. Acesso em: 5 dec. 2025.