APA (7th ed.) Citation

Forbes, F. A. (2011). Pope Pius the Tenth. Project Gutenberg.

Chicago Style (17th ed.) Citation

Forbes, F. A. Pope Pius the Tenth. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Forbes, F. A. Pope Pius the Tenth. Project Gutenberg, 2011.

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