Zhao M, Rudek MA, He P, Hafner FT, Radtke M, Wright JJ, Smith BD, Messersmith WA, Hidalgo M, Baker SD. A rapid and sensitive method for determination of sorafenib in human plasma using a liquid chromatography/tandem mass spectrometry assay. J Chromatogr B Analyt Technol Biomed Life Sci. 2007 Feb 01; 846(1-2):1-7.