D. C. Hooper, S. Spitsin, R. B. Kean, J. M. Champion, G. M. Dickson, I. Chaudhry and H. Koprowski, “Uric Acid, a Natural Scavenger of Peroxynitrite, in Experimental Allergic Encephalomyelitis and Multiple Sclerosis,” Proceedings of the National Academy of Science, USA, Vol. 95, No. 2, 1998, pp. 675-680. doi:10.1073/pnas.95.2.675
 T. S. Szasz, “The Myth of Mental Illness,” In: A. L. Caplan, J. J. McCartney and D. A. Sisti, Eds., Health, Disease, and Illness: Concepts in Medicine, Georgetown University Press, Washington DC, 2004, pp. 43-50.
 D. Eisenberg, S. E. Gollust, E. Golberstein and J. L. Hefner, “Prevalence and Correlates of Depression, Anxiety, and Suicidality among University Students,” American Journal of Orthopsychiatry, Vol. 77, No. 4, 2007, pp. 534-542. doi:10.1037/0002-94220.127.116.114
 R. L. Spitzer, K. Kroenke, J. B. W. Williams and The Patient Health Questionnaire Primary Care Group, “Validation and Utility of a Self-Report Version of PRIMEMD: The PHQ Primary Care Study,” Journal of the American Medical Association, Vol. 282, No. 18, 1999, pp. 1737-1744. doi:10.1001/jama.282.18.1737
 S. Becker, K. Al Zaid and E. Al Faris, “Screening for Somatization and Depression in Saudi Arabia: A Validation Study of the PHQ in Primary Care,” International Journal of Psychiatric Medicine, Vol. 32, No. 3, 2002, pp. 271-283.