6E.F.SCHUMACHER.Small is beautiful:economics as if people mattered[M].London:Everyman Press,1973.
7THERDORE.W.SCHULTZ.Transforming traditional agriculture[M].New Haven:Yale University Press,1964.
8Wallace,Vancrowder,Magnire.P.Policy options for agricultural education and training in sub-Saharan Africa:report of a preliminary study and literature review[R].AERDD Working Paper 96/1.Reading,UK:University of Reading,1996.
