APA (7th ed.) Citation

United States. Forest Service. (1990). Without a trace: The wilderness challenge. Forest Service, USDA.

Chicago Style (17th ed.) Citation

United States. Forest Service. Without a Trace: The Wilderness Challenge. [Washington, D.C.?]: Forest Service, USDA, 1990.

MLA (9th ed.) Citation

United States. Forest Service. Without a Trace: The Wilderness Challenge. Forest Service, USDA, 1990.

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