1. https://www.pbleiner.com/en/insights-news/news/cell-based-evidence-supports-bioactivity-collagen-peptides-skin-firmness-and-elasticity

2. https://onlinelibrary.wiley.com/doi/10.1111/jocd.12174

3. https://www.pbleiner.com/en/clinical-study-fsu-solugelr-improves-physical-and-mental-well-being-active-middle-aged-adults