Não informado. (1978). Farmer cooperatives. Department of Agriculture, Agricultural Cooperative Service.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Farmer Cooperatives. Washington: Department of Agriculture, Agricultural Cooperative Service, 1978.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Farmer Cooperatives. Department of Agriculture, Agricultural Cooperative Service, 1978.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.