APA (7th ed.) Citation

Johnson, R. B. (1961). Coal resources of the Trinidad coal field in Huerfano and Las Animas Counties, Colorado. United States Department of the Interior, Geological Survey.

Chicago Style (17th ed.) Citation

Johnson, Ross B. Coal Resources of the Trinidad Coal Field in Huerfano and Las Animas Counties, Colorado. Washington, D.C.: United States Department of the Interior, Geological Survey, 1961.

MLA (9th ed.) Citation

Johnson, Ross B. Coal Resources of the Trinidad Coal Field in Huerfano and Las Animas Counties, Colorado. United States Department of the Interior, Geological Survey, 1961.