KURASHVILI, T. A. Circular $m$-functions. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 46, n. 6, p. 776–781, 1994. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5707. Acesso em: 5 dec. 2025.