ZELINSKII, Yu. B. On a mapping of a projective space into a sphere. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 62, n. 7, p. 937–944, 2010. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2926. Acesso em: 5 dec. 2025.