SHAHZAD, N. A RESULT ON BEST APPROXIMATION. Tamkang Journal of Mathematics, [S. l.], v. 29, n. 3, p. 223–226, 1998. DOI: 10.5556/j.tkjm.29.1998.4273. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4273. Acesso em: 2 may. 2024.