1. Fresh-water mollusks of Cretaceous Age from Montana and Wyoming Author/Creator: Yen, Teng-Chien, author Publication/Creation: Washington : United States Department of the Interior, Geological Survey, 1951 Resource Type: Book Access & Availability: Loading
2. Fresh-water mollusks of Cretaceous Age from Montana and Wyoming Author/Creator: Yen, Teng-Chien Publication/Creation: Washington : U.S. Govt. Print. Off, 1951 Resource Type: Book Is Part Of: U.S. Geological Survey professional paper, no. 233 A-E. Access & Availability: Loading