TON, Dao-rong; HE, Kai-yao. Free Archimedean $l$-Groups. MATHEMATICA SCANDINAVICA, [S. l.], v. 74, p. 34–48, 1994. DOI: 10.7146/math.scand.a-12478. Disponível em: https://tidsskrift.dk/math/article/view/12478. Acesso em: 13 aug. 2026.