APA (7th ed.) Citation

Ernst, C. H., & Emerson, C. (2010). The Mark of the Knife. Project Gutenberg.

Chicago Style (17th ed.) Citation

Ernst, Clayton H., and Chase Emerson. The Mark of the Knife. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Ernst, Clayton H., and Chase Emerson. The Mark of the Knife. Project Gutenberg, 2010.

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