• http://www.molmetab.com/article/S2212-8778(17)30537-9/fulltext?rss%3Dyes
• https://www.ncbi.nlm.nih.gov/pubmed/18715218
• https://pubmed.ncbi.nlm.nih.gov/20920564/
• http://sciencebeta.com/gaba/
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5519190/
• https://www.ncbi.nlm.nih.gov/pubmed/25226827
• https://pubmed.ncbi.nlm.nih.gov/27335245/
• https://pubmed.ncbi.nlm.nih.gov/28632199/
• https://pubmed.ncbi.nlm.nih.gov/2912010/
• https://pubmed.ncbi.nlm.nih.gov/23075568/
• https://www.ulprospector.com/en/na/PersonalCare/Detail/5573/211347/Monoammonium-Glycyrrhizinate
• https://www.ncbi.nlm.nih.gov/pubmed/18006026
• https://www.ncbi.nlm.nih.gov/pubmed/10584049
• https://www.ncbi.nlm.nih.gov/pubmed/16176615
• https://www.ncbi.nlm.nih.gov/pubmed/17299107
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2651880/
• https://www.medicalnewstoday.com/articles/319370%2523risks-and-benefits
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6088424/
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6088424/
• https://www.organicfacts.net/grape-seed-extract.html
• https://www.herbalone.com/blog/5-great-benefits-of-grape-seed-extract/
• http://www.chm.bris.ac.uk/motm/tryptophan/supplement.html
• https://www.ncbi.nlm.nih.gov/pubmed/27983571/
• http://www.mdpi.com/1420-3049/18/7/7998/htm
• https://www.healthline.com/health/hypochlorhydria%23symptoms