Houshmand, Behzad, et al. “Efficacy of Conventional Laser Irradiation Versus a New Method for Gingival Depigmentation (Sieve Method): A Clinical Trial”. Journal of Lasers in Medical Sciences, vol. 8, no. 2, Apr. 2017, pp. 88-94, https://journals.sbmu.ac.ir/jlms/article/view/13046.