1. L. P. Smirnova, V. I. Glyzin, T. B. Shemeryankina, and E. F. Ob’edkova, RF Patent No. 2,032,413, (06.09.91);Byul. Izobret., No. 10 (1995).
2. S. S. Nikolaeva, L. P. Smirnova, V. A. Bykov, et al.,Khim.-Farm. Zh.,33(11), 25–27 (1999).
3. V. I. Glyzin, G. G. Nikolaeva, and T. D. Dargaeva,Natural Xanthones [in Russian], Nauka, Novosibirsk (1986), pp. 45, 67. 88.
4. M. E. Perel’son, Yu. N. Sheinker, and A. A. Savina,Spectra and Structures of Coumarins, Chromones, and Xanthones [in Russian], Meditsina, Moscow (1978), pp. 197–214.
5. M. Aritomi and T. Kawasaki,Chem. Pharm. Bull.,16(14), 760–761 (1968).