T. Marte Ljosaa, A. Stubhaug, C. Mork, T. Moum, and A. k. Wahl, “Improvement in Psoriasis Area and Severity Index Score Predicts Improvement in Skin Pain Over Time in Patients with Psoriasis”, Acta Derm Venereol, vol. 93, no. 3, pp. 330–334, Sep. 2012.