1. Ultrastructural studies on graptolites Author/Creator: Urbanek, Adam Publication/Creation: Washington : Smithsonian Institution Press; [for sale by the Supt. of Docs., U.S. Govt. Print. Off.], 1974-75. Resource Type: Book Access & Availability: Loading
2. Upper Cambrian-Lower Ordovician Notch Peak Formation in western Utah Author/Creator: Hintze, Lehi F. Publication/Creation: Denver, CO : For sale by the Books and Open-File Reports Section, U.S. Geological Survey Resource Type: Book Access & Availability: Loading
3. Upper Cambrian-Lower Ordovician Notch Peak Formation in western Utah Author/Creator: Hintze, Lehi F., author Publication/Creation: Washington : Department of the Interior, U.S. Geological Survey, 1988 Resource Type: Book Access & Availability: Loading
4. Upper Ordovician and Silurian stratigraphy in Sequatchie Valley and parts of the adjacent valley and ridge, Tennessee Author/Creator: Milici, Robert C., 1931- Publication/Creation: Washington : U.S. Govt. Print. Off, 1977 Resource Type: Book Is Part Of: U.S. Geological Survey professional paper, no. 995-999. Access & Availability: Loading
5. Upper Ordovician and Silurian stratigraphy in Sequatchie Valley and parts of the adjacent valley and ridge, Tennessee Author/Creator: Milici, Robert C., 1931- author Publication/Creation: Washington : United States Department of the Interior, Geological Survey, 1977 Resource Type: Book Access & Availability: Loading
6. Upper Ordovician ecology of the central Appalachians Author/Creator: Bretsky, Peter William, 1938- Publication/Creation: New Haven : Peabody Museum of Natural History, Yale University, 1970 Resource Type: Book Access & Availability: Loading
7. Upper Ordovician formations in the Maysville area, Kentucky Author/Creator: Peck, John H. Publication/Creation: Washington : U.S. Govt. Print. Off, 1966 Resource Type: Book Is Part Of: U.S. Geological Survey bulletin, no.1243-1244. Access & Availability: Loading
8. Upper Ordovician formations in the Maysville area, Kentucky Author/Creator: Peck, John H., 1937- author Publication/Creation: [Washington, D.C.] : United States Department of the Interior, Geological Survey, 1966 Resource Type: Book Access & Availability: Loading