Civilization, Subterranean

Free to read here, from Project Gutenberg.

The Coming Race

Edward Bulwer Lytton Lytton, Baron, also an audiobook

The Underground City; Or, The Black Indies

Jules Verne, also an audiobook

La race future

Edward Bulwer Lytton Lytton, Baron

French

Les Indes Noires

Jules Verne

French

Out of the Earth

George Edrich

Hiilikaivoksessa

Jules Verne

Finnish