Work was partly funded under a contract from the Joint Nature Conservation Committee on behalf of English Nature, the Countryside Council for Wales, and the Nature Conservancy Council for Scotland, and under a contract from the Department of the Environment for Northern Ireland.
Population processes in some British seed-eating birds by Humphrey Q. P. Crick. ISBN 0903793121. Published by British Trust for Ornithology in 1991. Publication and catalogue information, links to buy online and reader comments.