D. Ametefe, George, et al. “Comparison of Optimal Fungal Pectinase Activities Using the Box-Behnken Design: doi.org 10.26538 Tjnpr V5i9.21”. Tropical Journal of Natural Product Research (TJNPR), vol. 5, no. 9, Sept. 2021, pp. 1656-64, https://tjnpr.org/index.php/home/article/view/423.