RUS, Ioan A. ”Homogeneous” second order differential equation: zeros separation principles. Studia Universitatis Babeș-Bolyai Mathematica, [S. l.], v. 63, n. 2, p. 245–256, 2018. DOI: 10.24193/subbmath.2018.2.08. Disponível em: https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/2069. Acesso em: 5 feb. 2025.