| Author: | Simak, Clifford D., 1904-1988 |
| Subject: | PS, Time travel -- Fiction, Science fiction |
| Format: | Text |
| Date issued: | 2007 |
| Language: | English |
| Publisher: | Project Gutenberg, |
| Rights: | Public domain in the USA. |
| Download link: | Project Mastodon [electronic resource] / Clifford D. Simak |