4J. C. Cooper, "A Joint Framework for Analysis of Agri- Environmental Payment Programs", American Journal of Agricultural Economics, Vol. 85, No. 4 (Nov. 2003), pp. 976--987.
5D. Zilberman, L. Lipper and N. Mccarthy,"When Could Payments for Environmental Services Benefit the Poor? " Environment and Development Economics, Vol. 13 (May 2008), pp. 255--278.
6S. Wunder, "Payments for Environmental Services: Some Nuts and Bolts", No. 9 (May, 2005), http:// www. cifor, cgiar, org/pes/publications/pdf_ files/009 -- Infobrief. pdf.
7L. Fen, L. Wenhua and L. Moucheng, "Forest Eco-- compensation Mechanism.. A Survey", Ecological Economy, Vol. 4 (July 2007), pp115--126.