Cita APA (7th ed.)

Watt, K. E. F. (1973). Principles of environmental sciences. McGraw-Hill.

Cita Chicago (17th ed.)

Watt, Kenneth E. F. Principles of Environmental Sciences. Nueva York: McGraw-Hill, 1973.

Cita MLA (9th ed.)

Watt, Kenneth E. F. Principles of Environmental Sciences. McGraw-Hill, 1973.