Παραπομπή APA

Watt, K. E. (1973). Principles of environmental science. Mc Graw-Hill Book Co.

Παραπομπή Chicago Style

Watt, Kenneth E.F. Principles of Environmental Science. London: Mc Graw-Hill Book Co, 1973.

Παραπομπή MLA

Watt, Kenneth E.F. Principles of Environmental Science. Mc Graw-Hill Book Co, 1973.