Buckland, S.T., Baillie, S.R., Dick, J. McP., Elston, D.A., Magurran, A.E., Scott, E.M., Smith, R.I., Somerfield, P.J., Studeny, A.C. & Watt, A. 2012. How should regional biodiversity be monitored?. Environmental and Ecological Statistics 19: 606. doi:10.1007/s10651-012-0202-7