Gill, F; D Donsker, eds. (2011). "Waxwings to Swallows". IOC World Bird Names (version 2.9). Archived from the original on July 24, 2011. Retrieved 17 August 2011.
worldbirdnames.org
Gill, F; D Donsker, eds. (2011). "Waxwings to Swallows". IOC World Bird Names (version 2.9). Archived from the original on July 24, 2011. Retrieved 17 August 2011.