1. Tomimori T, Yoshimoto M (1980) Quantitative variation of glycyrrhizin in the decoction of Glycyrrhizae Radix mixed with other crude drugs. Shoyakugaku Zasshi 34:138–144
2. Takaishi K, Kuwajima H, Tokuda T, Endo M, Oda H, Tsuji E (1982) Studies on the procedure of making a decoction of Chinese medicinal preparation: studies on the extracting condition of ephedrine from Ephedra and the preparation combining Ephedra. Shoyakugaku Zasshi 36:245–249
3. Noguchi M, Kubo M, Hayashi T, Ono M (1978) Studies on the pharmaceutical quality evaluation of the crude drug preparations used in orient medicine “Kampoo” (I). Precipitation reaction of the components of Coptidis Rhizoma and these of Glycyrrhizae Radix or Rhei Rhizoma in decoction solution. Shoyakugaku Zasshi 32:104–110
4. Yi L, Xu X (2004) Study on the precipitation reaction between baicalin and berberine by HPLC. J Chromatogr B 810:165–168. https://doi.org/10.1016/j.jchromb.2004.07.007
5. Noguchi M (1978) Studies on the pharmaceutical quality evaluation of crude drug preparations used in orient medicine “Kampoo”. II. Precipitation reaction of berberine and glychyrrhizin in aqueous solution. Chem Pharm Bull 26:2624–2629. https://doi.org/10.1248/cpb.26.2624