KREIN, S. G.; SAPRONOV, I. V. One class of solutions of Volterra equations with regular singularity. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 3, p. 424–432, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5015. Acesso em: 5 dec. 2025.