APA (7th ed.) Citation

Keller, H. (2009). The World I Live In. Project Gutenberg.

Chicago Style (17th ed.) Citation

Keller, Helen. The World I Live In. Project Gutenberg, 2009.

MLA (9th ed.) Citation

Keller, Helen. The World I Live In. Project Gutenberg, 2009.

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