Enger, E. D., Bockarie, A. T., & Smith, B. F. (2006). Environmental science: Study of interrelationships (Tenth edition.). McGraw-Hill.

Enger, Eldon D., Anne Todd Bockarie, and Bradley F. Smith. Environmental Science: Study of Interrelationships. Tenth edition. Boston: McGraw-Hill, 2006.

Enger, Eldon D., et al. Environmental Science: Study of Interrelationships. Tenth edition. McGraw-Hill, 2006.