Dyfyniad APA

Graaff, J. d. (1996). The price of soil erosion: An economic evaluation of soil conservation and watershed development. Wageningen Agricultural University.

Dyfyniad Arddull Chicago

Graaff, J. de. The Price of Soil Erosion: An Economic Evaluation of Soil Conservation and Watershed Development. Wageningen, Netherlands: Wageningen Agricultural University, 1996.

Dyfyniad MLA

Graaff, J. de. The Price of Soil Erosion: An Economic Evaluation of Soil Conservation and Watershed Development. Wageningen Agricultural University, 1996.

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