1. M. D. Mashkovskii, Medicinal Agents [in Russian], Part 2, Meditsina, Moscow (2005).
2. Yu. B. Belousov and E. A. Ushkalova, Antibiot. Khimioter., 46, No. 11, 23–35 (2001).
3. A. Alwartham, S. A. Fattan, and N. Zahran, Talanta, 32, No. 6, 703–707 (1992).
4. C. Hendrix, J. Thomas, E. Roets, and J. Hoogmartens, J. Liq. Chromatogr., 16, No. 2, 421–445 (1993).
5. E. G. Kulapina, V. V. Baraguzina, and O. I. Kulapina, Zh. Anal. Khim., 59, No. 9, 971–975 (2004).