SMUTKUPT, S. Applying Lean Six Sigma to Improve Telephone Bill Payment: A Case Study of A Real Estate Developer. NIDA Case Research Journal, [S. l.], v. 14, n. 2, p. 87–109, 2023. DOI: 10.14456/ncrj.2022.4 . Disponível em: https://so04.tci-thaijo.org/index.php/NCRJ/article/view/263605. Acesso em: 1 oct. 2026.