Identification and quantification of 13 components in Angelica sinensis (Danggui) by gas chromatography – mass spectrometry coupled with pressurized liquid extraction - Lao, S C; Li, S P; Kan, K KW; Li, P; Wan, J B; Wang, Y T; Dong, T TX; Tsim, K WK (Anal Chim Acta, 2004)