MACEDONSKA-NOSALSKA, Olga. On infinite Nielsen transformations. MATHEMATICA SCANDINAVICA, [S. l.], v. 51, p. 63–86, 1982. DOI: 10.7146/math.scand.a-11965. Disponível em: https://www.mscand.dk/article/view/11965. Acesso em: 5 dec. 2025.