APA (7th ed.) Citation

O'Neill, E. (2003). The First Man. Project Gutenberg.

Chicago Style (17th ed.) Citation

O'Neill, Eugene. The First Man. Project Gutenberg, 2003.

MLA (9th ed.) Citation

O'Neill, Eugene. The First Man. Project Gutenberg, 2003.

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