9Just, Richard E.,Darrell L. Hueth, and Andrew Schmitz. The Welfare Economics of Public Policy: A Practical Approach to Project and Policy Evaluation[M]. Cheltenham, UK: Edward Elgar.
10Schwartza, Zvi, and Li-Chun Linb.The Impact of Fees on Visitation of National Parks[J].Tourism Management, 2006.(6): 1386-1396.