Não informado. (1891). Bulletin of the North Dakota Agricultural Experiment Station. North Dakota Agricultural Experiment Station.
Chicago-referens (17:e uppl.)Não informado. Bulletin of the North Dakota Agricultural Experiment Station. Fargo, ND: North Dakota Agricultural Experiment Station, 1891.
MLA-referens (8:e uppl.)Não informado. Bulletin of the North Dakota Agricultural Experiment Station. North Dakota Agricultural Experiment Station, 1891.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.