©David Delgado-Gomez, Inmaculada Peñuelas-Calvo, Antonio Eduardo Masó-Besga, Silvia Vallejo-Oñate, Itziar Baltasar Tello, Elsa Arrua Duarte, María Constanza Vera Varela, Juan Carballo, Enrique Baca-García. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 20.03.2017.
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