APA (7th ed.) Citation

O'Brien, G. A. T. (2004). An Essay on Mediæval Economic Teaching. Project Gutenberg.

Chicago Style (17th ed.) Citation

O'Brien, George Augustine Thomas. An Essay on Mediæval Economic Teaching. Project Gutenberg, 2004.

MLA (9th ed.) Citation

O'Brien, George Augustine Thomas. An Essay on Mediæval Economic Teaching. Project Gutenberg, 2004.

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