Julvez J, Forns M, Ribas-Fito N, Mazon C, Torrent M, Garcia-Esteban R, Ellison-Loschmann L, Sunyer J. Psychometric characteristics of the California Preschool Social Competence Scale in a spanish population sample. Early Educ Dev. 2008;19(5):795-815.
Urrutia I, Aguirre U, Sunyer J, Plana E, Muniozguren N, Martinez-Moratalla J. Changes in the prevalence of asthma in the Spanish cohort of the European Community Respiratory Health Survey (ECRHS-II). Arch. Bronconeumol. 2007 Aug;43(8):425-30.