APA-referens (7:e uppl.)

Birdsall, S. S., & Florin, J. (1992). Outline of american geography: Regional landscapes of the united states (Fourth edition.). John Wiley.

Chicago-referens (17:e uppl.)

Birdsall, Stephen S., och John Florin. Outline of American Geography: Regional Landscapes of the United States. Fourth edition. New York: John Wiley, 1992.

MLA-referens (9:e uppl.)

Birdsall, Stephen S., och John Florin. Outline of American Geography: Regional Landscapes of the United States. Fourth edition. John Wiley, 1992.