SKOLEM, Th. A New Version of Some Considerations of A. Thue. Mathematica Scandinavica, Berkeley, CA, United States, v. 8, p. 71–80, 1960. DOI: 10.7146/math.scand.a-10594. Disponível em: https://journals.msp.org/mscand/article/view/2752. Acesso em: 8 sep. 2026.