Functional social support : A systematic review and standardized comparison of different versions of the DUFSS questionnaire using the EMPRO tool - Lozano-Hernández, Cristina M. (Biosanitary Research and Innovation Foundation of Primary Care) ; Pardo Cladellas, Yolanda (Universitat Autònoma de Barcelona) ; Gil Conesa, Mario (Hospital General de Castellò) ; Garin, Olatz (Universitat Pompeu Fabra) ; Forés, Montserrat Ferrer (Institut Hospital del Mar d'Investigacions Mèdiques) ; del Cura-González, Isabel (Universidad Rey Juan Carlos)