8Costanza R, d\'Arge R, de Groot R, et al.The value of the world\'s ecosystem services and natural capital[J]. Nature, 1997, 387(5): 253-260.
9Moran D, Mcvittie A, Allcroft D J, et al. Quantifying public preferences for agri-environmental policy in Scotland: A comparison of methods[J]. Ecological Economics, 2007, 63(1): 42-53.
10Wuenscher T, Engel S, Wunder S. Spatial targeting of payments for environmental services: A tool for boosting conservation benefits[J]. Ecological Economics, 2008, 65(4): 822-833.