APA (7th ed.) Citation

Gallaher, Dahlman, & Gilmartin. (2009). Key concepts in political geography. Sage.

Chicago Style (17th ed.) Citation

Gallaher, Dahlman, and Gilmartin. Key Concepts in Political Geography. Thousand Oaks, CA: Sage, 2009.

MLA (8th ed.) Citation

Gallaher, et al. Key Concepts in Political Geography. Sage, 2009.