Biggs, Paul & Espach, Ralph H. Petroleum and Natural Gas Fields in Wyoming. [Washington D.C.]. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc38797/. Accessed January 26, 2015.
Note: Inconsistencies in capitalization and punctuation within the Digital Library may affect this citation. Before using this citation in formal writing, please consult your preferred style manual. More information.