Não informado. (1938). Bimonthly Bulletin of the North Dakota Agricultural Experiment Station. North Dakota Agricultural Experiment Station.
Chicago-viite (17. p.)Não informado. Bimonthly Bulletin of the North Dakota Agricultural Experiment Station. Fargo, ND: North Dakota Agricultural Experiment Station, 1938.
MLA-viite (8. p.)Não informado. Bimonthly Bulletin of the North Dakota Agricultural Experiment Station. North Dakota Agricultural Experiment Station, 1938.
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