BUSLAEV , A. G. Factorization of special integral operator. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 40, n. 6, p. 780–783, 1988. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/9291. Acesso em: 6 dec. 2025.