Cook, T.D., and Bally, A.W., eds., 1975, Stratigraphic atlas of North and Central America, prepared by the Exploration Department of Shell Oil Company, Houston, Texas. (Compiled by S. Milner, R.T. Buffler, R.E. Farmer, and D.K. Clark; Cartography and drafting by W.C. Heuer, J.W. Loofs, J.F. Laverde, and H.G. Villarreal, Jr.): Princeton, N.J., Princeton University Press, 272 p.
