Search U.S. government technical reports digitized or harvested by TRAIL.
Technology and use of lignite proceedings : Bureau of Mines-University of North Dakota Symposium, Grand Forks, N. Dak., April 1961
Technology and use of lignite :proceedings : Bureau of Mines-University of North Dakota Symposium, Grand Forks, N. Dak., April -May 1963
Technology and use of lignite :proceedings: Bureau of Mines - University of North Dakota Symposium, Bismarck, N. Dak., May 12-13, 1971