HARAH, M. Constructive representation at the plane collineations placing quadric itself. Lithuanian Mathematical Journal, [S. l.], v. 8, n. 4, p. 845–848, 1968. DOI: 10.15388/LMJ.1968.20615. Disponível em: https://www.journals.vu.lt/LMJ/article/view/20615. Acesso em: 6 dec. 2025.