GEHRING, F. W.; HAG, K.; MARTIO, O. Quasihyperbolic geodesics in John domains. Mathematica Scandinavica, Berkeley, CA, United States, v. 65, p. 75–92, 1989. DOI: 10.7146/math.scand.a-12267. Disponível em: https://journals.msp.org/mscand/article/view/1383. Acesso em: 24 jul. 2026.