BENDJEDDOU , Ahmed; BOUKOUCHA, Rachid. Explicit limit cycles of a cubic polynomial differential systems. Studia Universitatis Babeș-Bolyai Mathematica, [S. l.], v. 61, n. 1, p. 77–85, 2016. Disponível em: https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/5518. Acesso em: 5 feb. 2025.