Não informado. Extension Folder. North Carolina State College of Agriculture and Engineering, Agricultural Extension Service.
Chicago-Zitierstil (17. Ausg.)Não informado. Extension Folder. Raleigh, NC: North Carolina State College of Agriculture and Engineering, Agricultural Extension Service.
MLA-Zitierstil (8. Ausg.)Não informado. Extension Folder. North Carolina State College of Agriculture and Engineering, Agricultural Extension Service.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.