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Annual report of research and technologic work on coal, fiscal year 1937
Annual report of research and technologic work on coal fiscal year 1938
Annual report of research and technologic work on coal, fiscal year 1940
Annual report of research and technologic work on coal, fiscal year 1939
Annual report of research and technologic work on coal :fiscal year 1944
Annual report of research and technologic work on coal :fiscal year 1945
Annual report of research and technologic work on coal :fiscal year 1947
Annual report of research and technologic work on coal :fiscal year 1948
Annual report of research and technologic work on coal :fiscal year 1949