Pre-Sale Process Optimization for Improved Efficiency Using Six Sigma Tools. International Academic Research Journal of Business and Management, [S. l.], v. 4, n. 1, p. 17–23, 2015. Disponível em: https://www.acrpub.com/index.php/iarjbm/article/view/169.. Acesso em: 13 sep. 2025.