Beal, Carl H. The Decline and Ultimate Production of Oil Wells, with Notes on the Valuation of Oil Properties. Washington D.C.. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc12371/. Accessed February 1, 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.