Lerluck Chitradon, Polson Mahakhan, Vichien Kitpreechavanich, and Napha Lotong. 1992. “Optimization of Pectinase Production on Solid Substrates by Rhizopus sp. 26R Capable of Raw Cassava Starch Hydrolysis”. Agriculture and Natural Resources 26 (4). Bangkok, Thailand:374-83. https://li01.tci-thaijo.org/index.php/anres/article/view/241801.