Jeffrey, J., Situmeang , R. R. . ., & Christopher, C. (2021). The Effect of Product Quality, Responsiveness and Promotion on Customer Satisfaction at Pt Global Graha Sarana Abadi. Jurnal Mantik, 5(3), 2005-2012. Retrieved from https://iocscience.org/ejournal/index.php/mantik/article/view/1825