BirdLife International. 2016. Ardea herodias. The IUCN Red List of Threatened Species 2016: e.T22696998A93597223. Cygnus olor. Besøkt 28. januar 2018.
hbw.com
Carboneras, C. & Kirwan, G.M. (2019). Mute Swan (Cygnus olor). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/52803 on 8 June 2019).