1. C. D. Ibadullaeva and S. V. Serkerov, Khim. Prir. Soedin., 423 (2000).
2. I. I. Karyagin, Flora of Azerbaijan, Genus Heracleum L., Vol. 6, 1953, p. 495.
3. G. G. Kasumova and S. V. Serkerov, in: News of Gyanja Regional Scientific Centre, Azerbaijan National Academy of Sciences, No. 39, 26 (2010).
4. S. V. Serkerov and A. N. Aleskerova, Infrared Spectra and Structure of Sesquiterpene Lactones and Coumarins [in Russian], CBS Production, Baku, 2006.
5. G. A. Kuznetsova, Natural Coumarins and Furocoumarins [in Russian], Nauka, Leningrad, 1967.