Faraji, Hossein. “The Effect of Coffee-Enriched Chlorogenic Acid on Insulin, GIP and GLP-1 Levels in Healthy Humans: A Systematic Review”. Progress in Nutrition 21, no. 4 (December 16, 2019): 744-751. Accessed July 11, 2020. https://www.mattioli1885journals.com/index.php/progressinnutrition/article/view/6557.