APA (7th ed.) Citation

Onions, O. (2010). The Tower of Oblivion. Project Gutenberg.

Chicago Style (17th ed.) Citation

Onions, Oliver. The Tower of Oblivion. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Onions, Oliver. The Tower of Oblivion. Project Gutenberg, 2010.

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