Purkitt, H. E. (2007). Annual editions: World politics 06/07 (27th ed.). McGraw-Hill Contemporary Learning Series.
Citazione stile Chigago Style (17a edizione)Purkitt, Helen E. Annual Editions: World Politics 06/07. 27th ed. Dubuque, Iowa: McGraw-Hill Contemporary Learning Series, 2007.
Citatione MLA (8a ed.)Purkitt, Helen E. Annual Editions: World Politics 06/07. 27th ed. McGraw-Hill Contemporary Learning Series, 2007.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.