United States. Bureau of Mines.
Chamberlin, Rollin Thomas.
United States. Mine Safety and Health Administration.
John Nagy
Jim Eldridge
Kevin M. Cahill
James Ashworth
Ronald S. Conti
Joseph M. Singer
E.I. du Pont de Nemours & Company
George S. Rice
Hiltmar Schubert
Kirk V. Cammack
Unknown Author
Yuri Herrera
Kevin A. O'Neill
Ian Jones
Stuart Maslen
Charles E. Munroe