KUSSAINOVA, L. K. On oscillation of two terms linear differential equation with alternating potential. Eurasian Mathematical Journal, [S. l.], v. 3, n. 2, p. 135–140, 2012. Disponível em: https://emj.enu.kz/index.php/main/article/view/797. Acesso em: 31 oct. 2025.