Cita APA (7th ed.)

Johnson, G. (1976). Profitable pig farming (5a. ed.). Farming Press.

Cita Chicago (17th ed.)

Johnson, Geoffrey. Profitable Pig Farming. 5a. ed. Londres: Farming Press, 1976.

Cita MLA (9th ed.)

Johnson, Geoffrey. Profitable Pig Farming. 5a. ed. Farming Press, 1976.