1. Cornwall Wildlife Trust (1994) Cornwall Life Project: Project Specification. Cornwall Wildlife Trust, Truro
2. Department of the Environment (1989) Strategic Guidance for West Yorkshire: Regional Planning Guidance 2. HMSO, London
3. Department of the Environment (1993) Countryside Survey 1990. Department of the Environment, London
4. Freeman C (1997) The development of a landuse decision-making model for use on sites with naturally regenerating habitat. Unpublished Ph.D. thesis, Leeds Metropolitan University
5. Higgs G, Aitchison J, Bracken I, Crosweller H, Jones P (1994) The national GIS demonstrator for common lands for England and Wales. J. of Env. Plan. & Manag. 37(1): 33–49