Kohls, R. (2002). Marketing of agricultura; products (9th.). Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Kohls, Rochard. Marketing of Agricultura; Products. 9th. New Delhi: Prentice Hall, 2002.
Lua MLA (9ú heag.)Kohls, Rochard. Marketing of Agricultura; Products. 9th. Prentice Hall, 2002.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.