Cunningham, W. P., & Cunningham, M. A. (2009). Principles of environmental science: Inquiry & applications (5th edition.). McGraw-Hill.
Cita Chicago (17th ed.)Cunningham, William P., i Mary Ann Cunningham. Principles of Environmental Science: Inquiry & Applications. 5th edition. Dubuque, IA: McGraw-Hill, 2009.
Cita MLA (9th ed.)Cunningham, William P., i Mary Ann Cunningham. Principles of Environmental Science: Inquiry & Applications. 5th edition. McGraw-Hill, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.