British Birds Rarities Committee (2006) . Besøkt 22. april 2008. British Ornithologists' Union (2008) . Besøkt 22. april 2008. Clements, James F. (2007) , 6th ed., Cornell University Press, Ithaca, New York. Dudley, Steve P.; Mike Gee; Chris Kehoe; Tim M. Melling; The British Ornithologists' Union Records Committee (BOURC) (2006) The British List: A Checklist of Birds of Britain (7th edition), , 148 (3): 526–563. Evans, Ceri (2003) . Besøkt 22. april 2008. Green, Jonathan (2002) , Welsh Ornithological Society. Lovegrove, Roger; Graham Williams & Iolo Williams (1994) , T & AD Poyser Ltd, London. O'Shea, Brian (2000) , Skylark Books, Aberystwyth. Perrins, Christopher, (2004) , Oxford University Press, Oxford. Prater & Thorpe (2006) . Besøkt 22. april 2008. Pugh, Elfyn (2005) The Red Kite , . Besøkt 22. april 2008. Rogers, M. J. & the British Birds Rarities Committee (2004) Report on Rare birds in Great Britain in 2003, , 97:564. Snow, D. W. & Perrins, C. M. (1998) , Vol. 2, Oxford University Press, Oxford. Tipling, David (1996) , HarperCollins, London. Welsh Records Panel (2006) . Besøkt 22. april 2008. Welsh Records Panel (2007) . Besøkt 22. april 2008.