APA (7th ed.) Citation

Hartwell, E. C. (2005). The Teaching of History. Project Gutenberg.

Chicago Style (17th ed.) Citation

Hartwell, E. C. The Teaching of History. Project Gutenberg, 2005.

MLA (9th ed.) Citation

Hartwell, E. C. The Teaching of History. Project Gutenberg, 2005.

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