Grigg, D. B. (1974). The agricultural systems of the world: An evolutionary approach. Cambridge: Cambridge University Press.
Trích dẫn kiểu ChicagoGrigg, David B. The Agricultural Systems of the World: An Evolutionary Approach. Cambridge: Cambridge University Press, 1974.
Deismireacht MLAGrigg, David B. The Agricultural Systems of the World: An Evolutionary Approach. Cambridge: Cambridge University Press, 1974.
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