| Author: | Knox, Thomas Wallace, 1835-1896 |
| Subject: | HN, TN, Mines and mineral resources, Social history -- 19th century, Caves, Tunnels |
| Format: | Electronic text |
| Date issued: | 2018 |
| Language: | English |
| Publisher: | Project Gutenberg, |
| Rights: | Public domain in the USA. |
| Download link: | The Underground World : A mirror of life below the surface [electronic resource] / Thomas Wallace Knox |