Biendl, Martin, et al. “Rapid and Sensitive Determination of Pesticide Residues in Hops and Hop Products Using HPLC-MS MS and GC-MS MS”. BrewingScience, vol. 67, no. 9/10, Oct. 2014, pp. 108-15, https://brewingscience.de/index.php/brewingscience/article/view/369.