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Soil conservation and sustainable land use
by
J. de Graaff
Royal Tropical Institute, 1993
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The economics of coffee
by
J. de Graaff
Pudoc, 1986
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The Price of Soil Erosion
by
J. de Graaff
Backhuys Publishers, September 18, 1996
Paperback
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Theoretical welfare economics
by
J. de Graaff
Cambridge University Press, 1963
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