APA (7th ed.) Citation

Helleberg, C. G. (2011). A Book Written by the Spirits of the So-Called Dead. Project Gutenberg.

Chicago Style (17th ed.) Citation

Helleberg, C. G. A Book Written by the Spirits of the So-Called Dead. Project Gutenberg, 2011.

MLA (9th ed.) Citation

Helleberg, C. G. A Book Written by the Spirits of the So-Called Dead. Project Gutenberg, 2011.

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