Michael T. Pavelko
Antony Trew
Charles H. Hapgood
John M. Ferritto
Carter W. Roberts
Unknown Author
Malcolm Holland
R. T. Hanson
Lawrence A Freeman
Charles E. Heywood
Young, Lewis Emanuel
Robert Gottlieb
Hans Hausen
Ricketts, Charles M.D.
National Coal Board. Mining Department.
John D. Milliman
Multidisciplinary Conference on Sinkholes (1st 1984 Orlando, Fla.)
Samuel Y. Johnson
Michael C. Carpenter