BRONSTED, A. Convex Sets and Chebyshev Sets. MATHEMATICA SCANDINAVICA, [S. l.], v. 17, p. 5–16, 1965. DOI: 10.7146/math.scand.a-10760. Disponível em: https://www.mscand.dk/article/view/10760. Acesso em: 3 may. 2024.