@misc{Butts_Charles_(1863-1946)_Bulletin,
 author={Butts, Charles (1863-1946)},
 howpublished={online},
 publisher={Government Printing Office.},
 language={eng},
 type={journal},
 title={Bulletin 641-K. Coals in the area between Bon Air and Clifty, Tennessee},
 keywords={United States of America, geology, mineralogy, journals},
}