Ckuntachai, K., and S. . Poungsangsuk. “The Influence of Service Marketing Mix Quality and Service Quality on Customer Satisfaction of Private Elderly Care Centers in Bangkok”. RPU Journal of Business Administration, vol. 1, no. 2, Dec. 2022, pp. 1-17, https://so03.tci-thaijo.org/index.php/RPUBAJOURNAL/article/view/265342.