Riani Altinia S, Adhi Utama A. Servqual-Based Service Quality Optimization to Drive Profit Growth at ITTR English Course. Eduvest [Internet]. 2026Jun.22 [cited 2026Oct.7];6(6):7323-39. Available from: http://www.eduvest.greenvest.co.id.submitjurnal.id/index.php/edv/article/view/53298