F. Anthony and J. Krutilla, “Determination of Optimal Capacity of Resource Based Recreation Facilities,” Natural Resources Journal, Vol. 12, No. 3, 1972, pp. 417-444.
 A. Randall, B. Ives and C. Eastman, “Bidding Games for Valuation of Aesthetic Environmental Improvements,” Journal of Environmental Economics and Management, Vol. 1, 1974, pp. 132-149.
 K. Arrow, R. Solow, P. R. Portney et al., “Report of NOAA Panel on Contingent Valuations,” US Federal Register, Vol. 10, 1993, pp. 4601-4614.
 C. B. Richard, A. C. Patricia and J. M. Daniel, “Contingent Valuation,” In: D. W. Bromley, The Handbook of Environmental Economics, Blackwell Publishers Ltd, New Jersey, 1995, pp. 629-654.
 T. Swanson and B. Day, “Valuing Water Quality in China: Purpose, Approach and Policy,” Journal of Environmental Sciences, Vol. 11, No. 3, 1999, pp. 309-316.
 F. Carlsson and S. O. Johansson, “Willingness to Pay for Improved Air Quality in Sweden,” Applied Economics, Vol. 32, No. 1, 2000, pp. 661-669.
 P. Iamtpakul, K. Hokao and K. Teknomo, “Public Park Valuation Using Travel Cost Method,” Proceedings of the Eastern Asia Society for Transportation Studies, May 2005, pp. 1249-1264.
 M. Rodolfo, Nayga Jr, R. Woodward and W. Aiew, “Experiments on the Divergence between Willingness to Pay and Willingness To Accept,” Economics Bulletin, Vol. 17, No. 4, 2005, pp. 1-5.
 A. B. Morancho, A. Ma Fuertes-Eugenio and S. del Saz-Salazar, “A Comparison Of Empirical Models Used to Infer the Willingness to Pay in Contingent Valuation,” Empirical Economics, Vol. 30, 2005, pp. 235-244. doi:10.1007/s00181-005-0236-x
 J. B. Loomis, P. Kent, L. Strange et al., “Measuring the Total Economical Value of Restoring Ecosystem Services in an Impaired River Basin: Results From a Contingent Valuation Survey,” Ecological Economics, Vol. 33, No. 1, 2000, pp. 103-117. doi:10.1016/S0921-8009(99)00131-7
 B. S. Jorgensen, M. A. Wilson and T. A. Hebelein, “Fairness in the Contingent Valuation of Environmental Public Goods: Attitude toward Paying for Environmental Improvements at Two Levels of Scope,” Ecological Economics, Vol. 36, No. 1, 2001, pp. 133-148.
 D. Y. Xue, “Estimate the Economic Values of Biodiversity-Case Study of Changbai Mountain Nature Reserve,” China Environmental Science Press, Beijing, 1997, p. 11.
 S. B. Wang, P. J. Wang, Z. Y. Hu et al., “Assessing the landscape Services Value with Contingent Valuation Method: A Case Study on Suzhou Brook, Shanghai City,” Journal of Fudan University, Vol. 42, No. 3, 2003, pp. 463-475.
 Z. M. Xu, Z. Q. Zhang, G. D. Cheng et al., “Comparison and Application of Different Contingent Valuation Methods in Measuring Total Economic Value of Restoring Ejina Banners Ecosystem Services,” Acta Ecologica Sinica, Vol. 23, No. 9, 2003, pp. 1841-1850.
 J. Zhao and K. Yang, “Estimating Urban Inland River Ecosystem Services Value in Shanghai by Contingent Valuation Method,” Research of Environmental Sciences, Vol. 17, No. 2, 2004, pp. 49-52.
 M. J. Zhang, J. F. Fan, C. X. Hu et al., “Assessment of Total Economic Value of Improving Atmospheric Quality of Lanzhou,” Journal of Arid Land Resources & Environment, Vol. 18, No. 3, 2004, pp. 28-32.
 Y. Yu, E. D. Wang, A. L. Liu et al., “Documentation Study of Economic Valuation on Recreational Tourism Resources,” East China Economic Management, Vol. 23, No. 9, 2009, pp. 140-146.