SOBCZYK, A. The Obliquity-Type of a Set of Vectors. MATHEMATICA SCANDINAVICA, [S. l.], v. 21, p. 195–198, 1967. DOI: 10.7146/math.scand.a-10859. Disponível em: https://www.mscand.dk/article/view/10859. Acesso em: 3 may. 2024.