HUSTAD, Otte. Upper Semi-Continuity of Convex Functions and Openness of Affine Maps. Mathematica Scandinavica, Berkeley, CA, United States, v. 70, p. 43–77, 1992. DOI: 10.7146/math.scand.a-12386. Disponível em: https://journals.msp.org/mscand/article/view/1265. Acesso em: 24 jul. 2026.