APA (7th ed.) Citation

Sullivan, F. W., & Gage, G. W. (2009). The Harbor of Doubt. Project Gutenberg.

Chicago Style (17th ed.) Citation

Sullivan, Francis William, and George W. Gage. The Harbor of Doubt. Project Gutenberg, 2009.

MLA (9th ed.) Citation

Sullivan, Francis William, and George W. Gage. The Harbor of Doubt. Project Gutenberg, 2009.

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