APA (7th ed.) Citation

Darwin, C. The Variation of Animals and Plants under Domestication — Volume 2.

Chicago Style (17th ed.) Citation

Darwin, Charles. The Variation of Animals and Plants Under Domestication — Volume 2.

MLA (9th ed.) Citation

Darwin, Charles. The Variation of Animals and Plants Under Domestication — Volume 2.

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