HANSEN, A. B. On a certain class of polytopes associated with independence systems. MATHEMATICA SCANDINAVICA, [S. l.], v. 41, p. 225–241, 1977. DOI: 10.7146/math.scand.a-11716. Disponível em: https://tidsskrift.dk/math/article/view/11716. Acesso em: 14 aug. 2026.