Vinogradov, V G, and E M Auezov. “Numbers, Distribution and Breeding Success of Whooper Swans Cygnus Cygnus and Mute Swans C. Olor in Central Kazakhstan, USSR, in 1985 and 1987”. Wildfowl (April 16, 2013): 73–76. Accessed February 13, 2026. https://tidsskrift.dk/Wildfowl/article/view/154998.