THAHEEM, A. B.; DAELE, A. Van. A result on two one-parameter groups of automorphisms. Mathematica Scandinavica, Berkeley, CA, United States, v. 51, p. 261–274, 1982. DOI: 10.7146/math.scand.a-11980. Disponível em: https://journals.msp.org/mscand/article/view/1665. Acesso em: 25 jul. 2026.