Sook-Fern Yeo, Cheng-Ling Tan, Kah-Boon Lim, and Elaine Lam, “Influencing Factors of Facial Spa Treatment on Visit Intention: An Importance-Performance Matrix Analysis (IPMA) Approach”, IJBS, vol. 21, no. 3, pp. 1087–1100, Dec. 2020.