THAHEEM, A. B.; DAELE, A. Van. A result on two one-parameter groups of automorphisms. MATHEMATICA SCANDINAVICA, [S. l.], v. 51, p. 261–274, 1982. DOI: 10.7146/math.scand.a-11980. Disponível em: https://tidsskrift.dk/math/article/view/11980. Acesso em: 14 aug. 2026.