APA (7th ed.) Citation

Paul, E., Freud, S., & Paul, C. (2006). A Young Girl's Diary. Project Gutenberg.

Chicago Style (17th ed.) Citation

Paul, Eden, Sigmund Freud, and Cedar Paul. A Young Girl's Diary. Project Gutenberg, 2006.

MLA (9th ed.) Citation

Paul, Eden, et al. A Young Girl's Diary. Project Gutenberg, 2006.

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