Cherry, C., and A. H. . . Siregar. “Analysis of the Effect of Service Provision and Consumer Motivation on Consumer Purchases in Phone Store (Case Study on Metta Cell Denai)”. Jurnal Mantik, vol. 5, no. 4, Jan. 2022, pp. 2352-7, https://iocscience.org/ejournal/index.php/mantik/article/view/1980.