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 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
4. 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
5. Middle Ordovician carbonate shelf to deep-water basin deposition in the southern Appalachians Publication/Creation: Knoxville : University of Tennessee, Dept. of Geological Sciences, 1980 Resource Type: Book Access & Availability: Loading
6. Middle Ordovician rocks of the Tellico-Sevier Belt, Eastern Tennessee Author/Creator: Neuman, Robert B., 1920- Publication/Creation: Washington : U.S. Govt. Print. Off, 1955 Resource Type: Book Is Part Of: U.S. Geological Survey professional paper, no. 274. Access & Availability: Loading
7. Middle Ordovician rocks of the Tellico-Sevier Belt, Eastern Tennessee Author/Creator: Neuman, Robert B., 1920- author Publication/Creation: Washington : United States Department of the Interior, Geological Survey, 1955 Resource Type: Book Access & Availability: Loading