A. Hailu, W. L. Adamowicz and P. C. Boxall, “Complements, Substitutes, Budget Constrains and Valuation Application of a Multi-Program Environmental Valuation Method,” Environmental and Resource Economics, Vol. 3, No. 16, 2000, pp. 51-68.
 K. G. Wills, “Iterative Bid Design in Contingent Valuation and the Estimation of the Revenue Maximising Price for a Cultural Good,” Journal of Culture Economics, Vol. 4, No. 26, 2002, pp. 307-324.
 D. Whittington, “Ethical Issues with Contingent Valuation Surveys in Developing Countries: A Note on Informed Consent and Other Concerns,” Environmental and Resource Economics, Vol. 28, No. 4, 2004, pp. 507-515.
 J. R. Crooker and J. A. Herriges, “Parametric and Semi- Nonparametric Estimation of Willingness-to-Pay in the Dichotomous Choice Contingent Valuation Framework,” Environmental and Resource Economics, Vol. 27, No. 4, 2004, pp. 451-480.
 J. A. List and C. Gallet, “What Experimental Protocol Influence Disparities between Actual and Hypothetical Stated Values? Evidence from a Meta-Analysis,” Environmental and Resource Economics, Vol. 3, No. 20, 2002, pp. 241-254.
 D. C. Macmillan, et al., “Modelling the Nonmarket Environmental Costs and Benefits of Biodiversity Projects Using Contingent Valuation Data,” Environmental and Resource Economics, Vol. 4, No. 18, 2001, pp. 391-410.
 H. X. Li and S. Z. Liu, “Systematic Analysis on the Driving Force of Grassland Degradation in North Tibet—A Case Study in Naqu County of Tibet,” Research of Soil and Water Conservation, Vol. 6, No. 12, 2005, pp. 215- 217.
 S. l. Niou and G. M. Jiang, “Function of Artificial Grassland in Restoration of Degraded Natural Grassland and its Research Advance,” Chinese Journal of Applied Ecology, Vol. 9, No. 15, 2004, pp. 1662-1666.
 X. C. Gao, A. Y. Jiang and J. M. Li, “An Institutional Explanation of ‘Over Grazing’ and Institutional Design of a Control System,” Journal of Lanzhou University, Vol. 4, No. 32, 2004, pp. 116-120.
 Y. S. Ma, et al., “Study on Rehabilitating and Rebuilding Technologies for Degenerated Alpine Meadow in the Changjiang and Yellow River Source Region,” Pratacul- tural Science, Vol. 19, No. 9, 2002, pp. 1-5.
 D. X. Yue, W. L. Li and Z. Z. Li, “Analysis of AHP Strategic Decision for Grazing Management System and Ecological Restoration in the Alpine Wetland at Gannan in Gansu,” Acta Bot Boreal Occident Since, Vol. 2, No. 24, 2004, pp. 248-253.
 A. Clewell, J. Rieger and J. Munro, “Guidelines for Developing and Managing Ecological Restoration Projects,” 2nd Edition, Society for Ecological Restoration, 2000. http://www.ser.org/
 K. Arrow, et al., “Report of the NOAA Panel on Contingent Valuation Report to the General Council of the US National Oceanic and Atmospheric Administration,” Resources for the Future, Washington, D.C., 1993.
 A. L. D. Nunes, C. J. M. Jeroen and D. Bergh, “Can People Value Proection against Invasive Marine Specise? Evidence from a Joint TC-CV Survey in the Netherlands,” Environmental and Resource Economics, Vol. 5, No. 28, 2004, pp. 517-532.
 K. Veiten, H. F. Hoen and J. Strand, “Sequencing and the Adding-up Property in Contingent Valuation of Endangered Species: Are Contingent Non-Use Values Economic Values,” Environmental and Resource Economics, Vol. 6, No. 29, 2004, pp. 419-433.
 W. M. Hanemann, “The Economic Theory of WTP and WTA,” In: I. J. Bateman and K. G. Willis, Eds., Valuing Environmental Preferences: Theory and Practice of the Contingent Valuation Method in the US, EU, and Developing Countries, Oxford University Press, Edward Elgar Press, Great Britain, 1999, pp. 43-93.