RADZIEVSKII, G. V. Asymptotics of the fundamental system of solutions of a linear functional-differential equation with respect to a parameter. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 47, n. 6, p. 811–836, 1995. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5475. Acesso em: 6 dec. 2025.