G. C. · G. Cooper · Gale Susan Cooper
| title | ISBN-13 | year of publication |
|---|---|---|
| Billy the Kid's Pretenders Brushy Bill & John Miller | 978-0-9845054-0-1 | 2010 |
| Billy the Kid's Writings, Words, and Wit | 978-0-9845054-2-5 | 2012 |
| Inside Animals | 978-0-316-15618-9 | 1978 |
| Unicorn Moon | 978-0-525-44148-9 | 1984 |
Dutton · Gelcour Books · Hachette Book Group USA