FABRICIUS-BJERRE, Fr. On Helices in the Euclidean $n$-Space. MATHEMATICA SCANDINAVICA, [S. l.], v. 35, p. 159–164, 1974. DOI: 10.7146/math.scand.a-11543. Disponível em: https://tidsskrift.dk/math/article/view/11543. Acesso em: 14 aug. 2026.