APA (7th ed.) Citation

Hall, A., & Thompson, D. (2009). Gray Seal: Halichoerus grypus. Academic Press/Elsevier.

Chicago Style (17th ed.) Citation

Hall, Ailsa, and David Thompson. Gray Seal: Halichoerus Grypus. Academic Press/Elsevier, 2009.

MLA (9th ed.) Citation

Hall, Ailsa, and David Thompson. Gray Seal: Halichoerus Grypus. Academic Press/Elsevier, 2009.

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