Allen, J. L. (2008). Annual editions: Environment 07/08 (Twenty-sixth edition.). McGraw-Hill/Dushkin.
Chicago-viite (17. p.)Allen, John L. Annual Editions: Environment 07/08. Twenty-sixth edition. Dubuque, IA: McGraw-Hill/Dushkin, 2008.
MLA-viite (8. p.)Allen, John L. Annual Editions: Environment 07/08. Twenty-sixth edition. McGraw-Hill/Dushkin, 2008.
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