Landscape area data 1990 [Countryside Survey] - Barr, C.J.; Bunce, R.G.H.; Clarke, R.T.; Gillespie, M.K.; Hallam, C.J.; Howard, D.C.; Maskell, L.C.; Ness, M.J.; Norton, L.R.; Scott, R.J.; Scott, W.A.; Smart, S.M.; et al. (NERC Environmental Information Data Centre, 2016)