JOHANSEN, S. The Extremal Convex Functions. MATHEMATICA SCANDINAVICA, [S. l.], v. 34, p. 61–68, 1974. DOI: 10.7146/math.scand.a-11506. Disponível em: https://www.mscand.dk/article/view/11506. Acesso em: 28 apr. 2024.