Não informado. (2021). Farm Economics. Pennsylvannia State University, Cooperative Extension Service.
Chicago-Zitierstil (17. Ausg.)Não informado. Farm Economics. University Park, Pa: Pennsylvannia State University, Cooperative Extension Service, 2021.
MLA-Zitierstil (8. Ausg.)Não informado. Farm Economics. Pennsylvannia State University, Cooperative Extension Service, 2021.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.