C.  Nor, Albring, D., Ferraz, A. B. F., Schripsema, J., Pires, V., Sonnet, P., Guillaume, D., and von Poser, G. L., ?Phloroglucinol derivatives from four Hypericum species belonging to the Trigynobrathys section.?, Biochem. Syst. Ecol., vol. 32, pp. 517-519 (2004) -, 2004.

Z. Q.  Yin, Wang, Y., Ye, W. C., and Zhao, S. X., ?Chemical constituents of Hypericum perforatum (St. John's wort) growing in China.?, Biochem. Syst. Ecol., vol. 32, pp. 521-523 (2004) -, 2004.