McKee, E.D., Henbest, L.G., Douglass, R.C., Grant, R.E., Jr., and Dunkle, D.H., 1966, Age range of Supai Formation [abs.]: U.S. Geological Survey Professional Paper 550-A, p. A82.
McKee, E.D., Henbest, L.G., Douglass, R.C., Grant, R.E., Jr., and Dunkle, D.H.
U.S. Geological Survey Professional Paper 550-A, p. A82.
Biostratigraphy, [Supai Fm][Supai Group] - Pennsylvanian/Permian, (Aubrey Group),