@ARTICLE {30221,
author={J.  Martínez and F. Martins and S. G. V. González-Víllora and F. Campos},
doi={10.47197/retos.v0i39.80061 },
journal={Retos},
title={Estudio sobre la calidad percibida de los usuarios de fitness: a partir de sus características y preferencias según sexo y edad  (Study on the perceived quality of fitness users: based on their characteristics and preferences according to sex and age)},
year={2021},
month={January},
volume={1},
number={39},
pages={477-482},
ISSN={1579-1726}
}