R. Schmidt, P. Anderegg, and M. Biendl, “Umweltkontaminanten in Hopfen”, BrSc, vol. 56, no. 5/6, pp. 93–98, Jun. 2003, Accessed: May 30, 2026. [Online]. Available: https://brewingscience.de/index.php/brewingscience/article/view/578