1. Directive 2004/54/EC dated 29 April 2004 of European Parliament and of the council on minimum safety requirements for tunnels in the Trans-European Road Network.
2. NFPA® 502, 2011 Standard for Road Tunnels, Bridges, and Other Limited Access Highways.
3. EuroTAP (European Tunnel Assessment Programm) tunnel 2/2008, P. 46–47.
4. Fire size in tunnels, PhD thesis, Richard Oswald Carvel, 2004.
5. Comparative analysis of safety in tunnel, Nussbaumer Cornelia, Austrian Road Safety Board.