RUKASOV, V. I. Best n-Term Approximations in Spaces with Nonsymmetric Metric. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 55, n. 4, p. 500–509, 2003. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3923. Acesso em: 27 apr. 2025.