1. AOAC Official Methods of Analysis. 16th ed, Association of Official Analytical Chemists, Washington DC, USA, p 69-74 (1995)
2. Chang JP, Kil GJ, Lee GH, Ji YS, Kim BR, Kang KH, Kim MR, Song MR, Park JY, Doh ES. Change of inorganic component, reducing sugar, catalpol and benzo[a]pyrene contents of Rehmannia glutinosa Libosch. var. purpurea Makino by drying methods. Korean J Medicinal Crop Sci, 19, 501-507 (2011) 10.7783/KJMCS.2011.19.6.501
3. Chang IM. Liver-protective activities of aucubin derived from traditional oriental medicine. Res Commun Mol Pathol Pharmacol, 102, 189-204 (1998)
4. Chao JCJ, Chiang SW, Wang CC, Tsai YH, Wu MS. Hot water-extracted Lycium barbarum and Rehmannia glutinosa inhibit proliferation and induce apoptosis of hepatocellular carcinoma cells. World J Gastroenterol, 12, 4478-4484 (2006) 10.3748/wjg.v12.i28.4478, 16874858, PMC4125633
5. Folin O, Denis W. On phosphotungstic-phosphomolybdic compounds as color reagents. J Biol Chem, 12, 239-249 (1912)