Não informado. (1966). Resource Bulletin NC. North Central Forest Experiment Station, Forest Service.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Resource Bulletin NC. Saint Paul, Minn: North Central Forest Experiment Station, Forest Service, 1966.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Resource Bulletin NC. North Central Forest Experiment Station, Forest Service, 1966.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.