Search U.S. government technical reports digitized or harvested by TRAIL.
American Lignites: Geological Occurrence, Petrographic Composition, And Extractable Waxes
Annual report of research and technologic work on coal and related investigations :fiscal year 1952
Determination of moisture-holding capacity (bed moisture) of coal for classification by rank
The international systems of hard-coal classification and their application to American coals
Evaluation of an acid-extraction method for determining mineral matter in American coals