APA (7th ed.) Citation

Newcomb, S. (2006). The Reminiscences of an Astronomer. Project Gutenberg.

Chicago Style (17th ed.) Citation

Newcomb, Simon. The Reminiscences of an Astronomer. Project Gutenberg, 2006.

MLA (9th ed.) Citation

Newcomb, Simon. The Reminiscences of an Astronomer. Project Gutenberg, 2006.

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