Rizqi Ananda Putri, Nafi’ah and Sarianoferni 2021. The Differences Between Giving Topical Therapy of Extract Etanol 96% and 70% Spirulina Platensis on Density of Collagen Fiber in Traumatic Ulcer Healing. DENTA JURNAL KEDOKTERAN GIGI. 13, 1 (Aug. 2021), 25–33.