Rosida , Dedin Finatsiyatull, et al. “Effects of Papain Concentration and Hydrolysis Time on Degree of Hydrolysis and Glutamic Acid Content of Apple Snail Hydrolysate ”. Nusantara Science and Technology Proceedings, Apr. 2021, pp. 17-21, https://doi.org/10.11594/nstp.2021.0904.