Geological Survey (U.S.), Denson, N. M., & Crysdale, B. L. (1991). Geologic map showing total thickness of coal in the south half of the Powder River Basin, northeastern Wyoming. The Survey.
Chicago Style (17th ed.) CitationGeological Survey (U.S.), N. M. Denson, and Bonnie L. Crysdale. Geologic Map Showing Total Thickness of Coal in the South Half of the Powder River Basin, Northeastern Wyoming. Reston, Va.: The Survey, 1991.
MLA (9th ed.) CitationGeological Survey (U.S.), et al. Geologic Map Showing Total Thickness of Coal in the South Half of the Powder River Basin, Northeastern Wyoming. The Survey, 1991.
Warning: These citations may not always be 100% accurate.