Identification by high-performance liquid chromatography-diode array detection-mass spectrometry and quantification by highperformance liquid chromatography-UV absorbance detection of active constituents of Hypericum perforatum - Brolis,M.; Gavetta,B.; Fuzzati,N.; Pace,R.; Panzeri,F.; Peterlongo,F. (J Chromatogr A, 1998)