Flegg & Cox (1972) Movement of Black-headed Gulls from Colonies in England and Wales
Horton et. al (1984) The winter distribution of foreign Black-headed Gulls in the British Isles
MacKinnon & Coulson (1987) The temporal and geographical distribution of Continental Black-headed Gulls Larus ridibundus in the British Isles
Rock (1999) The efficacy of the colour-ringing system used for Herring Gulls Larus argentatus and Lesser Black-backed Gulls Larus fuscus in Bristol 1980-1997.
van Dijk et. al (2012) New longevity records of Black-headed Gull with comments on wear and loss of aluminium rings
More added soon!
