Jayani, Nikmatul I. E., et al. “Formulation and Evaluation of Two Types of Functional Beverage Granules Made of Extracts of Guava Leaves, Purple Sweet Potato and Cinnamon: doi.org 10.26538 Tjnpr V5i6.7”. Tropical Journal of Natural Product Research (TJNPR), vol. 5, no. 6, June 2021, pp. 1024-9, https://www.tjnpr.org/index.php/home/article/view/565.