| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Middle and Upper Ordovician Nautiloid Cephalopods of the Cincinnati Arch Region of Kentucky, Indiana, and Ohio | 978-99956-833-3-7 (99956-833-3-4) | 1995 |
C.F. · C. Frey · R. C. · R. F. · R. Frey · Robert C. · Robert F. · Robert Frey