1. Baldwin JH (1985) Environmental planning and management. Westview, Boulder CO, pp 216–242
2. Bennett JW (1982) Valuing the existence of a natural ecosystem. Search 13:232–235
3. Boyle KJ, Bishop RC, Welsh MP (1985) Starting point bias in contingent valuation bidding games. Land Econ 61:188–194
4. Buckley RC (1987) Environmental Planning Techniques. SADME, Adelaide
5. Churchman CW (1984) Willingness to pay and morality: a study of future values. In: Churchman CW (ed) Natural resource administration. Westview, Boulder CO, pp 71–76