Farming Systems Programme (Botswana) & Norman, D. W. (1994). Farming systems research approach: A primer for eastern and southern Africa. Farming Systems Programme.
Lua i Stíl Chicago (17ú heag.)Farming Systems Programme (Botswana) agus D. W. Norman. Farming Systems Research Approach: A Primer for Eastern and Southern Africa. Gaborone, Botswana: Farming Systems Programme, 1994.
Lua MLA (8ú heag.)Farming Systems Programme (Botswana) agus D. W. Norman. Farming Systems Research Approach: A Primer for Eastern and Southern Africa. Farming Systems Programme, 1994.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.