1. Andreassend, D.C., 1985. Technical Note No. 1—Traffic accidents and advertising signs. Australian Road Research Board 15(2), Victoria, Australia, pp. 103–105.
2. Barjonet, P.E., 1992. Les relations compliquées des transports avec l'environnement et la sécurité. Recherche Transports Sécurité, No. 34, France, pp. 63–68.
3. Bellia, V., 1992. Introdução à economia do meio ambiente. Lecture Notes—Revision 7, Brazil.
4. Brown, B., 1989. Effects of distracting stimuli on instantaneous tracking performance. Australian Road Research Board, AIR 459-1, Victoria, Australia.
5. Code of Federal Regulation (CFR), 1993. Title 23—Highways. Subchapter H—Right-of-way and environment. Part 750—Highway Beautification, rev. ed. US Government Printing Office, Washington DC, pp. 324–329.