| Authors(s) | Douglass, J. F. |
| Year | 1977 |
| Title | Supplement to the bibliography of the North American land tortoises (Genus Gopherus). Smithsonian Herpetol. Inform. Serv. (39): 1-18. |
| Authors(s) | Douglass, J. F. |
| Year | 1977 |
| Title | Supplement to the bibliography of the North American land tortoises (Genus Gopherus). Smithsonian Herpetol. Inform. Serv. (39): 1-18. |