SUMAEDI, Sik. Using iso 9001 to Improve Sales Operation Performance: A Case Study of Implementationf ISO 9001. International Research Journal of Business Studies, Jakarta, Indonesia, v. 2, n. 3, p. 183–194, 2009. DOI: 10.21632/. Disponível em: https://irjbs.prasetiyamulya.ac.id/index.php/jurnalirjbs/article/view/851. Acesso em: 4 dec. 2025.