LOS, G. A. On finding stability and instability regions of one differential equation of the third order with periodic coefficients. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 18, n. 4, p. 110–116, 1966. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8319. Acesso em: 6 dec. 2025.