Não informado. (1958). North Dakota Farm Research. North Dakota Agricultural Experiment Station.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रNão informado. North Dakota Farm Research. Fargo, ND: North Dakota Agricultural Experiment Station, 1958.
एमएलए (8वां संस्करण) प्रशस्ति पत्रNão informado. North Dakota Farm Research. North Dakota Agricultural Experiment Station, 1958.
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