Hydrogeochemistry of the upper part of the Fort Union group in the Gascoyne lignite strip-mining area, North Dakota / by Robert L. Houghton ... [et al.] ; prepared in cooperation with the U.S. Bureau of Land Management, the U.S. Environmental Protection Agency, and the North Dakota Geological Survey (U.S. Geological Survey professional paper ; 1340)
Hydrogeochemistry of the upper part of the Fort Union group in the Gascoyne lignite strip-mining area, North Dakota / by Robert L. Houghton ... [et al.] ; prepared in cooperation with the U.S. Bureau of Land Management, the U.S. Environmental Protection Agency, and the North Dakota Geological Survey
(U.S. Geological Survey professional paper ; 1340)