APA (7th ed.) Citation

Casey, J., & Euclid. (2007). The First Six Books of the Elements of Euclid. Project Gutenberg.

Chicago Style (17th ed.) Citation

Casey, John, and Euclid. The First Six Books of the Elements of Euclid. Project Gutenberg, 2007.

MLA (9th ed.) Citation

Casey, John, and Euclid. The First Six Books of the Elements of Euclid. Project Gutenberg, 2007.

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