M. Kupetz, M. Gastl, T. Becker, and T. Heinrich, “Assay for detecting technical proteolytic enzymes in beer”, BrSc, vol. 74, no. 1/2, pp. 10–16, Feb. 2021, Accessed: Nov. 13, 2025. [Online]. Available: https://brewingscience.de/index.php/brewingscience/article/view/169