8Shepherd G.S. Agricultural Price Analysis [M].Ames: Iowa State University Press, 1963: 45.
9Rausser G.C., Perloff G.M., Zusman P..The Food Marketing System: Relevance of Economic Efficiency Mea- sures[M].Ames: Iowa State University Press, 1987: 1-20.
10Anrooy R.V.Vertical Cooperation and Marketing Effi- ciency in the Agriculture Products Marketing Chain:A Na- tional Perspective from Vietnam [R/0L].FAO Working Paper, 2003.