1. R. Ya. Rzazade, Izv. Akad. Nauk Az. SSR, 3, 17 (1955).
2. P. P. Polyakov, Flora of Azerbaidzhan [in Russian], 8, Izd. AN AzSSR, Baku, 1961.
3. P. P. Polyakov, Flora of the USSR [in Russian], 26, Nauka, Leningrad, 1961.
4. L. J. Bellamy, The Infra-Red Spectra of Complex Molecules, 2nd Ed., Methuen & Co., London (1958).
5. A. G. Safarova, Dissertation, Inst. Bot., NAS Azerbaidzhan, Baku, 2002.