The fossil wood and lignites of the Potomac formation
By: by F.H. Knowlton
Published: 1889
Place of publication: Minneapolis
Language: eng
Number of pages: 106
Subjects: Fossil Trees; Lignite; Geology
Notes: "Paper read before Am. Assoc. Advance Sci. Cleveland meeting, Aug., 1888. Resume of Bulletin of U.S. Geol. Survey, (in press)."

From the American Geologist, vol. 3, 1899. (pages 99-106).