Ariyanti, A., Masruriati, E., Nurhidayah, N. and Widiyana, A. 2021. Optimization of Placuna Placenta Collagen Serum on Adolescent Skin. Indonesian Journal of Global Health Research. 3, 2 (Jun. 2021), 237-244. DOI:https://doi.org/10.37287/ijghr.v3i2.487.