APA (7th ed.) Citation

Ashley, G. H., & Glenn, L. C. (1906). Geology and mineral resources of part of the Cumberland Gap coal field, Kentucky. Department of the Interior, United States Geological Survey.

Chicago Style (17th ed.) Citation

Ashley, Geo. H., and L. C. Glenn. Geology and Mineral Resources of Part of the Cumberland Gap Coal Field, Kentucky. Washington: Department of the Interior, United States Geological Survey, 1906.

MLA (9th ed.) Citation

Ashley, Geo. H., and L. C. Glenn. Geology and Mineral Resources of Part of the Cumberland Gap Coal Field, Kentucky. Department of the Interior, United States Geological Survey, 1906.