Comparative metabolomics analysis on hematopoietic functions of herb pair Gui-Xiong by ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry and pattern recognition approach - Li, W; Tang, Y; Guo, J; Shang, E; Qian, Y; Wang, L; Zhang, L; Liu, P; Su, S; Qian, D; Duan, J (J Chromatogr A, 2014)