APA

U.S. Department of Transportation, Federal Highway Administration, Iowa State University & Technology Transfer Center. (1990). W-beam guardrail repair and maintenance. Washington DC: U.S. Department of Transportation.

Chicago

U.S. Department of Transportation, Federal Highway Administration, Iowa State University and Technology Transfer Center. 1990. W-beam guardrail repair and maintenance. Washington DC: U.S. Department of Transportation.

Harvard

U.S. Department of Transportation, Federal Highway Administration, Iowa State University and Technology Transfer Center. (1990). W-beam guardrail repair and maintenance. Washington DC: U.S. Department of Transportation.

MLA

U.S. Department of Transportation, Federal Highway Administration, Iowa State University and Technology Transfer Center. W-beam guardrail repair and maintenance. Washington DC: U.S. Department of Transportation. 1990.