Luciano JV, Barrada JR, Aguado J, Osma J, García-Campayo J. Bifactor analysis and construct validity of the HADS: a cross-sectional and longitudinal study in fibromyalgia patients. Psychological Assessment. 2014 Jun;26(2):395-406.
Johannes CB, Caro JJ, Hartz SC, Marrs R. Adverse effects of ovulatory stimulants: a review. Assist Reprod Rev. 1993;3:68-74.