Shen, Y.; Wang, T.; Zhou, C.; Wang, X.; Ding, X.; Tian, S.; Liu, Y.; Peng, G.; Xue, S.; Zhou, J. Prevalence of Acne Vulgaris in Chinese Adolescents and Adults: A Community-Based Study of 17,345 Subjects in Six Cities. Acta Derm Venereol 2011, 92, 40-44.