WENDEL, J. G. Brief Proof of a Theorem of Baxter. Mathematica Scandinavica, Berkeley, CA, United States, v. 11, p. 107–108, 1962. DOI: 10.7146/math.scand.a-10654. Disponível em: https://journals.msp.org/mscand/article/view/2692. Acesso em: 25 jul. 2026.