Statistical analysis of an indicator of population trends in farmland birds /
Freeman, S. N.
Baillie, S. R.
Gregory, R. D.
British Trust for Ornithology.
Royal Society for the Protection of Birds.
Thetford : British trust for Ornithology ; Sandy : Royal Society for the Protection of Birds,
2001.
A joint report by BTO and RSPB to the Ministry of Agriculture, Fisheries and Food.
Birds