Wandela, R. S., and E. Elisa. “RANCANG BANGUN SISTEM INFORMASI ADMINISTRASI PELANGGAN FITNESS BERBASIS WEB”. Computer and Science Industrial Engineering (COMASIE), vol. 1, no. 01, Nov. 2019, pp. 112-21, https://ejournal.upbatam.ac.id/index.php/comasiejournal/article/view/1569.