- ^ 1.0 1.1 Toshio Fukai; Junko Nishizawa; Taro Nomura. Variations in the chemical shift of the 5-hydroxyl proton of isoflavones; two isoflavones from licorice. Phytochemistry. 2002-07, 36 (1). doi:10.1016/S0031-9422(00)97042-0.
- ^ 2.0 2.1 Toshio Fukai; Zeng Lu; Juno Nishizawa; Wang Ying-Hua; Taro Nomura. Four isoprenoid-substituted flavonoids from Glycyrrhiza aspera. Phytochemistry. 1994-05, 36 (1). doi:10.1016/S0031-9422(00)97044-4.
- ^ 3.0 3.1 Min Yang; Wei Wang; Jianghao Sun; Yuying Zhao; Yi Liu; Hong Liang; De-an Guo. Characterization of phenolic compounds in the crude extract of Hedysarum multijugum by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry. Rapid Communications in Mass Spectrometry. 2007-01, 21 (23). doi:10.1002/RCM.3277.