Ruhl, J. F., & Cowdery, T. K. (2004). Regional ground-water-flow models of surficial sand and gravel aquifers along the Mississippi River between Brainerd and St. Cloud, central Minnesota. U.S. Dept. of the Interior, U.S. Geological Survey.
Chicago Style (17th ed.) CitationRuhl, J. F., and T. K. Cowdery. Regional Ground-water-flow Models of Surficial Sand and Gravel Aquifers Along the Mississippi River Between Brainerd and St. Cloud, Central Minnesota. Reston, Va.: U.S. Dept. of the Interior, U.S. Geological Survey, 2004.
MLA (9th ed.) CitationRuhl, J. F., and T. K. Cowdery. Regional Ground-water-flow Models of Surficial Sand and Gravel Aquifers Along the Mississippi River Between Brainerd and St. Cloud, Central Minnesota. U.S. Dept. of the Interior, U.S. Geological Survey, 2004.