Não informado. (1999). Miscellaneous Series. North Dakota Geological Survey.
Chicagoスタイル(17版)引用形式Não informado. Miscellaneous Series. Grand Forks, ND: North Dakota Geological Survey, 1999.
MLA(8版)引用形式Não informado. Miscellaneous Series. North Dakota Geological Survey, 1999.
警告: この引用は必ずしも正確ではありません.