Não informado. (1984). Current farm economics. Oklahoma Agricultural Experiment Station.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Current Farm Economics. Stillwater, Okla: Oklahoma Agricultural Experiment Station, 1984.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Current Farm Economics. Oklahoma Agricultural Experiment Station, 1984.
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