1. Twin Creek limestone (Jurassic) in the western interior of the United States Author/Creator: Imlay, Ralph W. 1908-1989, (Ralph Willard), author Publication/Creation: Washington : United States Department of the Interior, Geological Survey, 1967 Resource Type: Book Access & Availability: Loading
2. Twin Creek limestone (Jurassic) in the western interior of the United States, Author/Creator: Imlay, Ralph W. 1908-1989. (Ralph Willard) Publication/Creation: Washington : U.S. Govt. Print. Off, 1967 Resource Type: Book Is Part Of: U.S. Geological Survey professional paper, no. 537-540. Access & Availability: Loading