EFFECTIVENESS OF MARKETING-MIX STRATEGIES ON CUSTOMERS OF FITNESS ESTABLISHMENTS. PILOT AND PRELIMINARY STUDY IN THE CITY OF YAOUNDE (CAMEROON). Revue ISG [Internet]. 1 mai 2022 [cité 23 oct. 2026];5(2). Disponible sur: https://www.revue-isg.com/index.php/home/article/view/913