Citation
Fuller, R.J., Gregory, R.D., Gibbons, D.W., Marchant, J.H., Wilson, J.D., Baillie, S.R. & Carter, N. 1995. Population declines and range contractions among lowland farmland birds in Britain. Conservation Biology 9: 1411. doi:10.1046/j.1523-1739.1995.09061425.x