Gupta, MA, et al. “the Development of an Acne Quality of Life Scale: Reliability;Validity;And Relation to Subjective Acne Severity in Mild to Moderate Acne Vulgaris”. Acta Dermato-Venereologica, vol. 78, no. 6, Dec. 1998, pp. 451-6, doi:10.1080/000155598442773.