1. L. P. Nikonova, É. A. Yudovich, and G. K. Nikonov, in: Subjects of the Jubilee Scientific Conference of the Tashkent Pharmaceutical Institute [in Russian], Tashkent (1970), p. 89.
2. L. P. Nikonova and G. K. Nikonov, Khim. Prirodn. Soedin., 508 (1970).