PASCALEV, G. Invertible quadratic transformations in a projective plane. Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 88, p. 329–340, 1996. Disponível em: https://stipendii.uni-sofia.bg/index.php/fmi/article/view/392. Acesso em: 21 nov. 2024.