APA (7th ed.) Citation

Milne, A. A. (2004). Not that it Matters. Project Gutenberg.

Chicago Style (17th ed.) Citation

Milne, A. A. Not That It Matters. Project Gutenberg, 2004.

MLA (9th ed.) Citation

Milne, A. A. Not That It Matters. Project Gutenberg, 2004.

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