R. H. · R. HOPKINS · Ralph H. · Ralph Lee Hopkins
| title | ISBN-13 (ISBN-10) | year of publica- tion | other author(s) |
|---|---|---|---|
| Hiking Colorado's Geology | 978-0-89886-708-4 (0-89886-708-8) | 2000 | Lindy Birkel Hopkins |
| Hiking the Southwest's Geology: Four Corners Region | 978-0-89886-856-2 (0-89886-856-4) | 2002 | |