GERUS, O. F. An estimate for the modulus of continuity of a quaternion singular Cauchy integral. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 62, n. 10, p. 1428–1435, 2010. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2967. Acesso em: 5 dec. 2025.