1. Modulation by immune function by food: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC538513/
  2. Immune function and micronutrient requirement change over the life course: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6212925/
  3. The role of psychological well-being in boosting immune system: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5876785/
  4. The immune system: a target for functional food? https://www.ncbi.nlm.nih.gov/pubmed/12495459
  5. Vitamin A: infection and immune function: https://www.ncbi.nlm.nih.gov/pubmed/11375434
  6. Can vitamin A mediate immunity and inflammation? https://www.ncbi.nlm.nih.gov/pubmed/25864736    
  7. Effects of different cooking methods on content of vitamins: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049644/  
  8. Science direct: Beta-carotene: https://www.sciencedirect.com/topics/food-science/beta-carotene
  9. Retention of vitamin C in drying processes of fruits and vegetable: https://ucanr.edu/datastoreFiles/608-216.pdf
  10. Kinetika deštrukcie vitamínov: http://www.vup.sk/en/download.php?bulID=249?start
  11. Ako naštartovať váš imunitný systém? https://www.health.harvard.edu/staying-healthy/how-to-boost-your-immune-system
  12. Význam baktérií mliečneho kvasenia pre degradáciu fytátu počas fermentácie: https://www.ncbi.nlm.nih.gov/pubmed/17373819