Borelli, C., Merk, K., Schaller, M., Jacob, K., Vogeser, M., Weindl, G., … Plewig, G. (2006). In vivo porphyrin production by P. acnes in untreated acne patients and its modulation by acne treatment. Acta Dermato-Venereologica, 86(4), 316–319. https://doi.org/10.2340/00015555-0088