1. https://www.sciencedirect.com/science/article/abs/pii/S0378874111003540

2. https://www.healthline.com/nutrition/birch-sap#benefits https://home.liebertpub.com/publications/journal-of-medicinal-food/38/overview

3. Berardi RR, DeSimone EM, Newton GD, Oszko MA, Popovich NG, Rollins CJ, Shimp LA, Tietze KJ, editors. Handbook of Nonprescription Drugs: An Interactive

Approach to Self-Care, 13th edition. Washington (DC): American Pharmaceutical Association; 2002.

4. Blumenthal M, Busse W, Goldberg A, Gruenwald J, Hall T, Riggins C, Rister R, editors. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin (TX): American Botanical Council; 1998.

5. Bradley PR, editor. British Herbal Compendium: A Handbook of Scientific Information on Widely Used Plant Drugs, Volume 2. Bournemouth (UK): British Herbal

Medicine Association; 2006.7. Nutrients for Prevention of Macular Degeneration and Eye- Related Disease. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6523787