APA (7th ed.) Citation

Hardart, F. E. (2007). The Beast of Space. Project Gutenberg.

Chicago Style (17th ed.) Citation

Hardart, F. E. The Beast of Space. Project Gutenberg, 2007.

MLA (9th ed.) Citation

Hardart, F. E. The Beast of Space. Project Gutenberg, 2007.

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