APA (7th ed.) Citation

Darwin, C., & Darwin, F. (2000). Life and Letters of Charles Darwin - Volume 1. Project Gutenberg.

Chicago Style (17th ed.) Citation

Darwin, Charles, and Francis Darwin. Life and Letters of Charles Darwin - Volume 1. Project Gutenberg, 2000.

MLA (9th ed.) Citation

Darwin, Charles, and Francis Darwin. Life and Letters of Charles Darwin - Volume 1. Project Gutenberg, 2000.

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