Koulakiotis NS, Pittenauer E, Halabalaki M, Tsarbopoulos A, Allmaier G. Comparison of different tandem mass spectrometric techniques (ESI?IT, ESI?and IP?MALDI?QRTOF and vMALDI?TOF/RTOF) for the analysis of crocins and picrocrocin from the stigmas of Crocus sativus L. Rapid Communications in Mass Spectrometry. 2012;26(6):670-678.