Ardamatskaya TB, Korzyukov AI. Numbers and distribution of Mute Swans Cygnus olor Whooper Swans C. cygnus and Bewick’s Swans C. bewickii in the Black Sea area of the Ukraine, USSR. Wildfowl [Internet]. 2013 Apr. 16 [cited 2025 Dec. 17];:53-5. Available from: https://tidsskrift.dk/Wildfowl/article/view/155007