Não informado. (2001). Pig improvement services. Meat and Livestock Commission.
Cita Chicago Style (17a ed.)Não informado. Pig Improvement Services. Bletchley, Inglaterra: Meat and Livestock Commission, 2001.
Cita MLA (8a ed.)Não informado. Pig Improvement Services. Meat and Livestock Commission, 2001.
Precaución: Estas citas no son 100% exactas.