by Orth, Charles J., Gilmore, James S., Knight, Jere D., Pillmore, Charles L., Tschudy, Robert H., Fassett, James E.
Published in Science (American Association for the Advancement of Science) (18.12.1981)

by Fassett, Jonathon E.
Published in Topology and its applications (28.04.2004)

by TRIPLEHORN, D, FASSETT, J. E, MOORE, T. A, CALLCOTT, T. G, SLUCHER, E. R
Published in International journal of coal geology (1990)