GUNAWAN, H.; JAMALUDIN, M.; PRATAMADIRDJA, M. D. On Birkhoff Angles in Normed Spaces. Journal of the Indonesian Mathematical Society, [S. l.], v. 27, n. 3, p. 270–284, 2021. DOI: 10.22342/jims.27.3.1030.270-284. Disponível em: http://jims-a.org./index.php/jimsa/article/view/1030. Acesso em: 5 oct. 2024.