García Fernández J, Fernández Gavira J. Programas y servicios para personas mayores en centros de fitness de Sevilla (Programs and services for older people in fitness centers in Seville). Retos [Internet]. 2010 Jan. 1 [cited 2025 Nov. 1];17:90-2. Available from: http://www.revistaretos.org/index.php/retos/article/view/34681