APA (7th ed.) Citation

Clevenger, W. (1992). Why the sky is blue: Other wonders of the Earth. Mallard Press.

Chicago Style (17th ed.) Citation

Clevenger, William. Why the Sky Is Blue: Other Wonders of the Earth. New York, N.Y: Mallard Press, 1992.

MLA (9th ed.) Citation

Clevenger, William. Why the Sky Is Blue: Other Wonders of the Earth. Mallard Press, 1992.