ZAVIZION, G. V. Asymptotic solution of a system of integro-differential equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 12, p. 1617–1623, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5166. Acesso em: 6 dec. 2025.