BLIJ, H. J. (1974). Essentials of geography: Regions and concepts. John Wiley and Sons.
Lua i Stíl Chicago (17ú heag.)BLIJ, Harm J. Essentials of Geography: Regions and Concepts. New York: John Wiley and Sons, 1974.
Lua MLA (9ú heag.)BLIJ, Harm J. Essentials of Geography: Regions and Concepts. John Wiley and Sons, 1974.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.