APA (7th ed.) Citation

Gregor, E. R. (2011). The War Trail. Project Gutenberg.

Chicago Style (17th ed.) Citation

Gregor, Elmer Russell. The War Trail. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Gregor, Elmer Russell. The War Trail. Project Gutenberg, 2011.

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