1997 IUCN red list of threatened plants (1997)

Botanischer Jahresbericht - Just, Johann Leopold, 1841 -1891 (Gebr. Borntraeger, 1879)

An environmental profile of the Black Sea Coast - Gillett, Harriet J. (WCMC, 1997)

Flora Orientalis : sive, Enumeratio plantarum in Oriente a Graecia et Aegypto ad Indiae fines hucusque observatarum - Boissier, Edmond, 1810 -1885 (H. Georg, 1867)