C. Steuer, P. Schuetz, L. Bernasconi, and A. R. Huberc, “Quantification of Quaternary Ammonium Compounds Against Surrogate Matrix by HILIC-MS/MS: Highlights of Analytical Sciences in Switzerland”, Chimia, vol. 71, no. 9, p. 601, Sep. 2017, doi: 10.2533/chimia.2017.601.