Ikramov, M. T.; Khalmatov, Kh. Kh.; Batirov, E. Kh.; Malikov, V. M. Chemistry of Natural Compounds, 1986 , vol. 22, # 2 p. 230 - 231 Khimiya Prirodnykh Soedinenii, 1986 , # 2 p. 245 - 246