APA (7th ed.) Citation

Gray, E. (2010). Familiar Talks on Science-World-Building and Life. Earth, Air and Water. Project Gutenberg.

Chicago Style (17th ed.) Citation

Gray, Elisha. Familiar Talks on Science-World-Building and Life. Earth, Air and Water. Project Gutenberg, 2010.

MLA (9th ed.) Citation

Gray, Elisha. Familiar Talks on Science-World-Building and Life. Earth, Air and Water. Project Gutenberg, 2010.

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