APA (7th ed.) Citation

Hanson, W. J., & Groen, G. (1977). Pollution and conservation. Longman.

Chicago Style (17th ed.) Citation

Hanson, William John, and Gerard Groen. Pollution and Conservation. London: Longman, 1977.

MLA (9th ed.) Citation

Hanson, William John, and Gerard Groen. Pollution and Conservation. Longman, 1977.

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