APA (7th ed.) Citation

Gatenby, R. M., & Humbert, J. M. (1991). Sheep. Macmillan.

Chicago Style (17th ed.) Citation

Gatenby, Ruth M., and J. M. Humbert. Sheep. London: Macmillan, 1991.

MLA (9th ed.) Citation

Gatenby, Ruth M., and J. M. Humbert. Sheep. Macmillan, 1991.