| 其他書名 | Cedar Valley, Shell Rock & Lime Creek : Guidebook for the Thirtieth Annual Tri-State Geological Field Conference, October 15 and 16, 1966, Headquarters, Mason City, Iowa |
| 出版 | Department of Geology, Northern Illinois University, 1967 |
| URL | http://books.google.com.hk/books?id=BieOSoMbT1MC&hl=&source=gbs_api |