A review of large-scale generic population monitoring schemes in Europe /
Marchant, John H.
Forrest, Claire.
Greenwood, Jeremy J. D.
Royal Society for the Protection of Birds.
European Bird Census Council.
British Trust for Ornithology.
Thetford : British Trust for Ornithology,
1998.
"A report to the Royal Society for the Protection of Birds on behalf of the European Bird Census Council"