Ruiz-Villaverde, R., M. A. Díaz-Martinez, and D. Sánchez-Cano. “Multiple Clustered Dermatofibromas Following Ustekinumab Treatment for Psoriasis Vulgaris”. Sultan Qaboos University Medical Journal, vol. 17, no. 3, Aug. 2017, pp. 375-7, doi:10.18295/squmj.2017.17.03.025.