Hamdi, Hamed A., et al. “The Role of Polyurethane Foam Modified With Feather As an Oil Sorbent: doi.org 10.26538 Tjnpr V5i7.9”. Tropical Journal of Natural Product Research (TJNPR), vol. 5, no. 7, July 2021, pp. 1219-22, https://www.tjnpr.org/index.php/home/article/view/480.