Farming Systems Programme (Botswana) & Norman, D. W. (1994). Farming systems research approach: A primer for eastern and southern Africa. Farming Systems Programme.
Chicago-viite (17. p.)Farming Systems Programme (Botswana) ja D. W. Norman. Farming Systems Research Approach: A Primer for Eastern and Southern Africa. Gaborone, Botswana: Farming Systems Programme, 1994.
MLA-viite (8. p.)Farming Systems Programme (Botswana) ja D. W. Norman. Farming Systems Research Approach: A Primer for Eastern and Southern Africa. Farming Systems Programme, 1994.
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