APA (7th ed.) Citation

Milne, A. A. (2008). Happy Days. Project Gutenberg.

Chicago Style (17th ed.) Citation

Milne, A. A. Happy Days. Project Gutenberg, 2008.

MLA (9th ed.) Citation

Milne, A. A. Happy Days. Project Gutenberg, 2008.

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