APA (7th ed.) Citation

Butler, E. P. (2013). How it Feels to be Fifty. Project Gutenberg.

Chicago Style (17th ed.) Citation

Butler, Ellis Parker. How It Feels to Be Fifty. Project Gutenberg, 2013.

MLA (9th ed.) Citation

Butler, Ellis Parker. How It Feels to Be Fifty. Project Gutenberg, 2013.

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