Thermospray Liquid Chromatography/Mass Spectrometry (LC-MS) Analysis of the Alkaloids from Cinchona ledgeriana Shoot and Cinchona robusta Shoot and Compact Globular Structures (CGS) Cultures - Giroud, C; van der Leer, T; Verpoorte, R; Heeremans, C E M; Niessen, W M A (Planta Medica, 1989)