MACEDONSKA-NOSALSKA, Olga. On infinite Nielsen transformations. Mathematica Scandinavica, Berkeley, CA, United States, v. 51, p. 63–86, 1982. DOI: 10.7146/math.scand.a-11965. Disponível em: https://journals.msp.org/mscand/article/view/1681. Acesso em: 25 jul. 2026.