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.
Fondell E, Balter O, Rothman KJ. Dietary intake and supplement use of vitamins C and E and upper respiratory tract infection. J Am Coll Nutr. 2011 Aug 1;30(4):248-58.
Hunt SM, McKenna SP, Doward LC. Preliminary report on the development of a disease-specific instrument for assessing quality of life of adults with growth hormone deficiency. Acta Endocrinol. 1993 Jun 1;128(Suppl 2):37-40.