Health Harvard Publishing. https://www.health.harvard.edu/blog/skin-serum-what-it-can-and-cant-do-2018061214029
Diakses pada 13 Januari 2021Healthline. https://www.healthline.com/health/benefits-of-face-serum#how-to-use
Diakses pada 13 Januari 2021Healthline. https://www.healthline.com/health/beauty-skin-care/order-of-skin-care#night-routine
Diakses pada 13 Januari 2021Stylecraze. https://www.stylecraze.com/articles/difference-between-a-toner-essence-serum-and-ampoule/
Diakses pada 13 Januari 2021Derm Store. https://www.dermstore.com/blog/how-to-layer-serums/
Diakses pada 13 Januari 2021Skin Kraft. https://skinkraft.com/blogs/articles/face-serum
Diakses pada 13 Januari 2021