APA (7th ed.) Citation

Ashworth, W. (1991). The encyclopedia of environmental studies. Facts on File.

Chicago Style (17th ed.) Citation

Ashworth, William. The Encyclopedia of Environmental Studies. New York Oxford: Facts on File, 1991.

MLA (9th ed.) Citation

Ashworth, William. The Encyclopedia of Environmental Studies. Facts on File, 1991.

Warning: These citations may not always be 100% accurate.