1. E. V. Vul’f, Tr. Prikl. Bot. Genet. Sel., 20, 347 (1929).
2. E. P. Kemertelidze, Chemical Investigation of Digitalis ciliata [in Russian], Metsniereba, Tbilisi (1977), p. 172.
3. E. P. Kemertelidze, L. N. Gvazava, and B. K. Chlaidze, Russ. Pat. No. 1689 (1999).
4. L. N. Gvazava and E. P. Kemertelidze, USSR Pat. No. 611427; Byull. Izobret., No. 2394451 (1978).
5. C. Sannie and H. Lapin, Bull. Soc. Chim., 4, 1080 (1952).