Não informado. (1958). North Dakota Farm Research. North Dakota Agricultural Experiment Station.
Chicago-Zitierstil (17. Ausg.)Não informado. North Dakota Farm Research. Fargo, ND: North Dakota Agricultural Experiment Station, 1958.
MLA-Zitierstil (8. Ausg.)Não informado. North Dakota Farm Research. North Dakota Agricultural Experiment Station, 1958.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.