APA (7th ed.) Citation

Doyle, A. C. (1996). The Vital Message. Project Gutenberg.

Chicago Style (17th ed.) Citation

Doyle, Arthur Conan. The Vital Message. Project Gutenberg, 1996.

MLA (9th ed.) Citation

Doyle, Arthur Conan. The Vital Message. Project Gutenberg, 1996.

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