M. Biendl and B. Foster, “New International Calibration Standard (ICS-A1) for HPLC Analysis of Alpha-Acids in Beer: Submitted on behalf of the International Hop Standards Committee”, BrSc, vol. 72, no. 11/12, p. 187, Dec. 2019, Accessed: May 30, 2026. [Online]. Available: https://brewingscience.de/index.php/brewingscience/article/view/256