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2. A. V. Kamernitskii, N. K. Abubakirov, M. B. Gorovits, Yu. S. Vollerner, N. E. Boishvillo, I. G. Reshetova, and V. A. Paseshnichenko, The Chemistry of the Spirostanols [in Russian], Nauka, Moscow (1986).
3. Dorith Onken and D. Onken, Pharmazie,35, 193 (1980).
4. P. K. Kintya, G. V. Lazur'evskii, N. N. Balashova, I. T. Balashova, A. I. Suruzhiu, and V. A. Lyakh, The Structure and Biological Activities of Steroid Glycosides of the Spirostan and Furostan Series [in Russian], Shtiintsa, Kishinev (1987).
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