United States. Department of the Interior. (1920). Regulations concerning coal mining leases, permits, and licenses under Act of Feb. 25, 1920 (Public No. 146). GPO.
Chicago Style (17th ed.) CitationUnited States. Department of the Interior. Regulations Concerning Coal Mining Leases, Permits, and Licenses Under Act of Feb. 25, 1920 (Public No. 146). [Washington]: GPO, 1920.
MLA (9th ed.) CitationUnited States. Department of the Interior. Regulations Concerning Coal Mining Leases, Permits, and Licenses Under Act of Feb. 25, 1920 (Public No. 146). GPO, 1920.
Warning: These citations may not always be 100% accurate.