APA (7th ed.) Citation

Huxley, T. H. (2001). On the Study of Zoology. Project Gutenberg.

Chicago Style (17th ed.) Citation

Huxley, Thomas Henry. On the Study of Zoology. Project Gutenberg, 2001.

MLA (9th ed.) Citation

Huxley, Thomas Henry. On the Study of Zoology. Project Gutenberg, 2001.

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