APA (7th ed.) Citation

Burroughs, E. R. (1996). At the Earth's Core. Project Gutenberg.

Chicago Style (17th ed.) Citation

Burroughs, Edgar Rice. At the Earth's Core. Project Gutenberg, 1996.

MLA (9th ed.) Citation

Burroughs, Edgar Rice. At the Earth's Core. Project Gutenberg, 1996.

Warning: These citations may not always be 100% accurate.