APA (7th ed.) Citation

Jacobs, W. W. (2007). Sea Urchins. Project Gutenberg.

Chicago Style (17th ed.) Citation

Jacobs, W. W. Sea Urchins. Project Gutenberg, 2007.

MLA (9th ed.) Citation

Jacobs, W. W. Sea Urchins. Project Gutenberg, 2007.

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