Tоdоrоv P. G. On the theory of Riccati’s equation. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 18, n. 1, p. 137–139, 1966. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8666. Acesso em: 6 dec. 2025.