5[7]Shaw J H.Introduction to wildlife management[M].New York:McGraw-Hill lnc,1985:316.
6[8]Boyle J,Bishop R C.The total value of wildlife resources:conceptual and empirical issues[M]//Association of Environmental and Resource Economics Workshop on Recreation Demand Modeling.Colorado:Boulder,1985.
7[9]Weisbred B A.Collective-consumption services of individualconsumption goods[J].Quarterly Journal of Economies,1964(78):471-477.
