United States. Bureau of Mines, Pennsylvania. Bureau of Topographic and Geologic Survey, Ashley, G. H., Sisler, J. D., & Reese, J. F. (1926). Bituminous coal fields of Pennsylvania (2nd ed.). Dept. of Forests and Waters, Topographic and Geologic Survey.
Chicago Style (17th ed.) CitationUnited States. Bureau of Mines, Pennsylvania. Bureau of Topographic and Geologic Survey, Geo. H. Ashley, James D. Sisler, and John F. Reese. Bituminous Coal Fields of Pennsylvania. 2nd ed. Harrisburg, Pa.: Dept. of Forests and Waters, Topographic and Geologic Survey, 1926.
MLA (9th ed.) CitationUnited States. Bureau of Mines, et al. Bituminous Coal Fields of Pennsylvania. 2nd ed. Dept. of Forests and Waters, Topographic and Geologic Survey, 1926.
Warning: These citations may not always be 100% accurate.