1. WHO. WHO|The Global Strategy and Action Plan on Ageing and Health (WHO, Geneva, 2020).
2. Vaughn, A. R., Clark, A. K., Sivamani, R. K. & Shi, V. Y. Natural oils for skin-barrier repair: Ancient compounds now backed by modern science. Am. J. Clin. Dermatol. 19, 103–117 (2018).
3. Honari, G. & Maibach, H. Skin structure and function. In Applied Dermatotoxicology (eds Honari, G. & Maibach, H.) 1–10 (Elsevier, Amsterdam, 2014).
4. Walling, R. E. Dermis: Structure, Composition and Role in Thermoregulation (Nova Science Publishers, Inc., Hauppauge, 2014).
5. Abels, C. & Angelova-Fischer, I. Skin care products: Age-appropriate cosmetics. In Current Problems in Dermatology (eds Surber, C. et al.) 173–182 (Karger AG, Basel, 2018).