Hariyadi, Dewi M., et al. “Formulation of Peel-Off Mask Containing Natural Antibacterial: Study on Poly Vinyl Alcohol (PVA) and Virgin Coconut Oil (VCO) Contents: doi.org 10.26538 Tjnpr V5i3.16”. Tropical Journal of Natural Product Research (TJNPR), vol. 5, no. 3, Mar. 2021, pp. 514-8, https://www.tjnpr.org/index.php/home/article/view/734.