Chemical and biological assessment of a traditional Chinese herbal decoction prepared from Radix Astragali and Radix Angelicae Sinensis: orthogonal array design to optimize the extraction of chemical constituents - Song, Z H; Ji, Z H; Lo, C K; Dong, T TX; Zhao, K J; Li, O TW; Haines, C J; Kung, S D; Tsim, K WK (Planta Med, 2004)