LING, BAOMING, et al. “Preliminary Evaluation of Papain: Its Enzymatic Characteristics and Effects on Growth Performance and Nutrient Digestibility in Weaned Piglets”. The Indian Journal of Animal Sciences, vol. 82, no. 12, Dec. 2012, pp. 1564–1569, https://doi.org/10.56093/ijans.v82i12.25696.