APA (7th ed.) Citation

Porter, V. (1993). Pigs: A handbook of the breeds of the world. Helm Information.

Chicago Style (17th ed.) Citation

Porter, Valerie. Pigs: A Handbook of the Breeds of the World. Mountfield, East Sussex: Helm Information, 1993.

MLA (9th ed.) Citation

Porter, Valerie. Pigs: A Handbook of the Breeds of the World. Helm Information, 1993.