APA (7th ed.) Citation

Gale Group, Shekhar, S., & Xiong, H. (2008). Encyclopedia of GIS. Springer.

Chicago Style (17th ed.) Citation

Gale Group, Shashi Shekhar, and Hui Xiong. Encyclopedia of GIS. New York: Springer, 2008.

MLA (9th ed.) Citation

Gale Group, et al. Encyclopedia of GIS. Springer, 2008.