APA (7e ed.) Bronvermelding

Allen, J. L. (2008). Annual editions: Environment 07/08 (Twenty-sixth edition.). McGraw-Hill/Dushkin.

Chicago (17e ed.) Bronvermelding

Allen, John L. Annual Editions: Environment 07/08. Twenty-sixth edition. Dubuque, IA: McGraw-Hill/Dushkin, 2008.

MLA (8e ed.) Bronvermelding

Allen, John L. Annual Editions: Environment 07/08. Twenty-sixth edition. McGraw-Hill/Dushkin, 2008.