Não informado. Extension farm news. North Carolina Agricultural Extension Service.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Extension Farm News. Raleigh, NC: North Carolina Agricultural Extension Service.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Extension Farm News. North Carolina Agricultural Extension Service.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.