Witono, Yuli, .Aulanni’am, and Simon Bambang Widjanarko. “Purification and Partial Characterization of Protease from Biduri (Calotropis Gigantea) Latex”. Jurnal Teknologi dan Industri Pangan 18, no. 1 (1): 1. Accessed August 8, 2020. http://dthh.journal.ipb.ac.id/index.php/jtip/article/view/369.