Assessing the Quality of Architectural Works in Underground Metro Stations in Egypt Via Six Sigma Methodology. International Journal of Current Engineering and Technology, [S. l.], v. 10, n. 6, p. 944–951, 2020. Disponível em: https://ijcet.evegenis.org/index.php/ijcet/article/view/1433. Acesso em: 12 mar. 2026.