Indexing winter gull populations in England, Wales, Scotland and Northern Ireland : an analysis of data from the 1953 to 2004 Winter Gull Roost Surveys /
Burton, N. H. K.
British Trust for Ornithology.
Thetford : British Trust for Ornithology,
2005.
"Draft report of work carried out by the British Trust for Ornithology under contract to English Nature, the Countryside Council for Wales, Scottish Natural Heritage, the Environment & Heritage Service (Northern Ireland), the Joint Nature Conservation Committee and Northumberland Water Ltd."
Includes bibliography (p. 21-24).
Gulls