Muksin, Abdullah, et al. “Determinants of Customer’s Equity: An Empirical Studies on BPRS Customers in Ex Banyumas Residency Central Java”. International Review of Management and Marketing, vol. 8, no. 2, Mar. 2018, pp. 81-89, https://mail.econjournals.com/index.php/irmm/article/view/6186.