MARKOV, S. On the algebraic properties of convex bodies and related algebraic systems. Ann. Sofia Univ. Fac. Math. and Inf., [S. l.], v. 91, p. 41–59, 1999. Disponível em: https://stipendii.uni-sofia.bg/index.php/fmi/article/view/268. Acesso em: 4 dec. 2024.