Santos, Michael. “Development and Preliminary Validation of a Questionnaire for Assessing Fitness Centers ”. Jurnal SPORTIF : Jurnal Penelitian Pembelajaran 10, no. 1 (May 1, 2024): 157-170. Accessed July 3, 2024. https://ojs.unpkediri.ac.id/index.php/pjk/article/view/22124.