"Report of work carried out by the British Trust for Ornithology under contract to Environment & Heritage Services" -- t.p.
Declines in over-wintering diving ducks at Lough Neagh and Lough Beg : comparisons of within site, regional, national and European trends by Ilya Maclean. ISBN 9781906204068. Published by British Trust for Ornithology in 2006. Publication and catalogue information, links to buy online and reader comments.