Cita APA (7a ed.)
Okigbo, B. (1974). The IITA farming systems program. International Center for Research in Semi-Arid Tropics.
Cita Chicago Style (17a ed.)
Okigbo, B. The IITA Farming Systems Program. International Center for Research in Semi-Arid Tropics, 1974.
Cita MLA (9a ed.)
Okigbo, B. The IITA Farming Systems Program. International Center for Research in Semi-Arid Tropics, 1974.
Precaución: Estas citas no son 100% exactas.