| Author: | Aycock, Roger D., 1914-2004 |
| Subject: | PS, Science fiction, Earth (Planet) -- Fiction, Human-alien encounters -- Fiction, Short stories |
| Format: | Text |
| Date issued: | 2021 |
| Language: | English |
| Publisher: | Project Gutenberg, |
| Rights: | Public domain in the USA. |
| Download link: | Ultimatum [electronic resource] / Roger D. Aycock |