Sulistiyo, Joko, et al. “Antioxidant Activity of Diadema Setosum Gonads from Kelapa Island, District of Seribu Island, Indonesia: doi.org 10.26538 Tjnpr V5i5.3”. Tropical Journal of Natural Product Research (TJNPR), vol. 5, no. 5, May 2021, pp. 809-13, https://www.tjnpr.org/index.php/home/article/view/579.