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by Shedd, Solon, 1860-1941
Published 1924 -
Coal in Washington;distribution geology mining preparation uses and economic value of coal resources of WashingtonBookby Daniels, Joseph, 1884-1965
Published 1934 -
Report on the mining industries of the United States (exclusive of the precious metals)with special investigation into the iron resources of the republic and into the Cretaceous coals of the NorthwestBookby Pumpelly, Raphael, 1837-1923
Published 1886