1. Composition, clay mineralogy, and diagenesis of the Simpson Group (Middle Ordovician), Grady County, Oklahoma Author/Creator: Pollastro, Richard M., author Publication/Creation: [Reston, Va.] : U.S. Department of the Interior, U.S. Geological Survey, 1991 Resource Type: Book Access & Availability: Loading
2. Composition, clay mineralogy, and diagenesis of the Simpson Group (Middle Ordovician), Grady County, Oklahoma Author/Creator: Pollastro, Richard M. Publication/Creation: [Washington, D. C.] : U.S. G.P.O. ; Denver, CO : For sale by the Books and Open-File Reports section, 1991 Resource Type: Book Access & Availability: Loading