Adams, W. W.; Geyer, L. E. & Parry, M. G. Coal-Mine Accidents in the United States, 1936. Washington D.C.. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc12583/. Accessed April 28, 2016.
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.