SEPPÄLÄ, Mika; SORVALI, Tuomas. Traces of commutators of Möbius transformations. Mathematica Scandinavica, Berkeley, CA, United States, v. 68, p. 53–58, 1991. DOI: 10.7146/math.scand.a-12345. Disponível em: https://journals.msp.org/mscand/article/view/1287. Acesso em: 24 jul. 2026.