1. The Martinsburg formation (Middle and Upper Ordovician) in the Delaware Valley, Pennsylvania-New Jersey Author/Creator: Drake, Avery Ala, 1927- Publication/Creation: [Washington] : [U.S. Govt. Print. Off], [1967] Resource Type: Book Is Part Of: U.S. Geological Survey bulletin, no.1243-1244. Access & Availability: Loading
2. The Martinsburg formation (Middle and Upper Ordovician) in the Delaware Valley, Pennsylvania-New Jersey : a clarification of the stratigraphy of clastic rocks of Middle and Late Ordovician age in western New Jersey and eastern Pennsylvania Author/Creator: Drake, Avery Ala, 1927- Publication/Creation: [Washington, D.C.] : United States Department of the Interior, Geological Survey, 1967 Resource Type: Book Access & Availability: Loading
3. Middle and Late Ordovician solitary rugose corals of the Cincinnati Arch region Author/Creator: Elias, Robert J. Publication/Creation: Alexandria, VA : For sale by the Distribution Branch, U.S. Geological Survey Resource Type: Book Is Part Of: U.S. Geological Survey professional paper, no. 1066 A-N. Access & Availability: Loading
4. Middle and Late Ordovician solitary rugose corals of the Cincinnati Arch region Author/Creator: Elias, Robert J., author Publication/Creation: Washington : United States Department of the Interior, Geological Survey, 1983 Resource Type: Book Access & Availability: Loading
5. Middle and Lower Ordovician formations in southernmost Nevada and adjacent California Author/Creator: Ross, Reuben James, 1918- author Publication/Creation: Washington, D.C. : United States Department of the Interior, Geological Survey, 1964 Resource Type: Book Access & Availability: Loading
6. Middle and Lower Ordovician formations in southernmost Nevada and adjacent California Author/Creator: Ross, Reuben James, 1918- Publication/Creation: Washington [D.C.] : U.S. G.P.O., 1964 Resource Type: Book Access & Availability: Loading
7. Middle and Upper Ordovician nautiloid cephalopods of the Cincinnati arch region of Kentucky, Indiana, and Ohio Author/Creator: Frey, Robert C., author Publication/Creation: Washington : U.S. Department of the Interior, U.S. Geological Survey, 1995 Resource Type: Book Access & Availability: Loading
8. Middle and Upper Ordovician nautiloid cephalopods of the Cincinnati arch region of Kentucky, Indiana, and Ohio Author/Creator: Frey, Robert C. Publication/Creation: Denver, CO : For sale by U.S. Geological Survey, Information Services Resource Type: Book Access & Availability: Loading
9. Middle and Upper Ordovician symmetrical univalved mollusks (Monoplacophora and Bellerophontina) of the Cincinnati arch region Author/Creator: Wahlman, G. P. (Gregory Paul), author Publication/Creation: Washington : U.S. Department of the Interior, U.S. Geological Survey, 1992 Resource Type: Book Access & Availability: Loading
10. Middle and Upper Ordovician symmetrical univalved mollusks (Monoplacophora and Bellerophontina) of the Cincinnati arch region Author/Creator: Wahlman, G. P. (Gregory Paul) Publication/Creation: Washington : U.S. G.P.O., 1992 Resource Type: Book Access & Availability: Loading