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Borrell C, Plasència A, Pasarin I, Ortún V.Borrell C, et al.J Epidemiol Community Health. 1997 Dec;51(6):659-67. doi: 10.1136/jech.51.6.659.J Epidemiol Community Health. 1997.PMID: 9519129Free PMC article.
Villalbí JR, Guarga A, Pasarín MI, Gil M, Borrell C.Villalbí JR, et al. Among authors: borrell c.Aten Primaria. 1998 Jan;21(1):47-54.Aten Primaria. 1998.PMID: 9557357Spanish.