JÓNSSON, Bjarni; MCKENZIE, Ralph. Powers of partially ordered sets: Cancellation and reffinement properties. MATHEMATICA SCANDINAVICA, [S. l.], v. 51, p. 87–120, 1982. DOI: 10.7146/math.scand.a-11966. Disponível em: https://www.mscand.dk/article/view/11966. Acesso em: 5 dec. 2025.