KINA, Abdelkrim; BERBACHE, Aziza; BENDJEDDOU, Ahmed. A class of differential systems of even degree with exact non-algebraic limit cycles. Studia Universitatis Babeș-Bolyai Mathematica, [S. l.], v. 65, n. 3, p. 403–410, 2020. DOI: 10.24193/subbmath.2020.3.08. Disponível em: https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/2580. Acesso em: 5 feb. 2025.