1. Journal of Laws of the Republic of Poland, Annex to nru 220, pos. 2181 of 23 December 2003, Detailed technical conditions for road signs, signals, traffic safety equipment and conditions for locating them on the road (2003)
2. NCHRP Report 711, Guidance for the selection, use, and maintenance of cable barrier systems (Washington DC, 2012)
3. FHWA, W-Beam Guardrail Repair: A Guide for Highway and Street Maintenance Personnel (U.S. Department of Transportation, 2008)
4. AASHTO, Maintenance Manual for Roadways and Bridges, 4th Edition (American Association of State Highway and Transportation Officials, Washington, 2007)