Identification of catechin oligomers from apple (Malus pumila cv. Fuji) in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and fast-atom bombardment mass spectrometry. - Ohnishi-Kameyama,M.; Yanagida,A.; Kanda,T.; Nagata,T. (Rapid Commun Mass Spectrom, 1997)