| Author: | Walton, Frank, 1870-1959 |
| Subject: | PZ, Mystery and detective stories, Aeronautics -- Juvenile fiction |
| Format: | Electronic text |
| Date issued: | 2015 |
| Language: | English |
| Publisher: | Project Gutenberg, |
| Rights: | Public domain in the USA. |
| Download link: | The Flying Machine Boys on Duty; Or, The Clue Above the Clouds [electronic resource] / Frank Walton |