Dunbar, G. S. (1991). Modern geography: An encyclopedic survey. Garland.
Lua i Stíl Chicago (17ú heag.)Dunbar, Gary S. Modern Geography: An Encyclopedic Survey. New York: Garland, 1991.
Lua MLA (9ú heag.)Dunbar, Gary S. Modern Geography: An Encyclopedic Survey. Garland, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.