KLEE, Victor; OLECH, Czeslaw. Characterizations of a Class of Convex Sets. Mathematica Scandinavica, Berkeley, CA, United States, v. 20, p. 290–296, 1967. DOI: 10.7146/math.scand.a-10839. Disponível em: https://journals.msp.org/mscand/article/view/2487. Acesso em: 25 jul. 2026.