CUNNINGHAM, W. P., CUNNINGHAM, M. A., & SAIGO, B. W. (2003). Environmental science: A global concern.-- ed.7. McGraw-Hill.

CUNNINGHAM, William P., Mary Ann CUNNINGHAM, and Barbara Woodworth SAIGO. Environmental Science: A Global Concern.-- Ed.7. Boston: McGraw-Hill, 2003.

CUNNINGHAM, William P., et al. Environmental Science: A Global Concern.-- Ed.7. McGraw-Hill, 2003.