KRISTENSEN, L. Invariant Metrics in Coset Spaces. MATHEMATICA SCANDINAVICA, [S. l.], v. 6, p. 33–36, 1958. DOI: 10.7146/math.scand.a-10532. Disponível em: https://www.mscand.dk/article/view/10532. Acesso em: 2 may. 2024.