Suiyarti, W. et al. 2025. Determination of SPF (Sun Protection Factor) Value in Sunscreen Formulation of Vetiveria Zizanioides L. Essential Oil. Jurnal Penelitian Pendidikan IPA. 11, 4 (Apr. 2025), 224–227. DOI:https://doi.org/10.29303/jppipa.v11i4.10893.