Paul, J., A. T. Dagrosa, Y. Chen, P. Gangar, D. Ressler, and M. S. Chapman. “Photodynamic Therapy With δ-Aminolevulinic Acid and Blue Light for the Treatment of Actinic Cheilitis”. SKIN The Journal of Cutaneous Medicine, vol. 4, no. 4, July 2020, pp. 357-60, doi:10.25251/skin.4.4.14.