Garcia-Esteve L, Torres A, Navarro P, Aguado J, Ascaso C. Maternidad the planned y psicomorbilidad: un riesgo evitable / Unplanned pregnancy and psychological morbidity: an avoidable risk. Fac Med Barc. 2005 Jul;32(3):111-8.
Derby CA, Araujo AB, Johannes CB, Feldman HA, McKinlay JB. Measurement of erectile dysfunction in population-based studies: the use of a single question self-assessment in the Massachusetts Male Aging Study. Int J Impot Res. 2000 Aug 1;12(4):197-204.