VÄISÄLÄ, Jussi. Metric duality in Euclidean spaces. Mathematica Scandinavica, Berkeley, CA, United States, v. 80, p. 249–288, 1997. DOI: 10.7146/math.scand.a-12620. Disponível em: https://journals.msp.org/mscand/article/view/1009. Acesso em: 25 jul. 2026.