APA

PIARC. XVIIIth world road congress. Brussels 13-19, Sept 1987, . (1987). Belgian roads. Innovations. Paris: PIARC. XVIIIth world road congress. Brussels 13-19.

Chicago

PIARC. XVIIIth world road congress. Brussels 13-19, Sept 1987, . 1987. Belgian roads. Innovations. Paris: PIARC. XVIIIth world road congress. Brussels 13-19.

Harvard

PIARC. XVIIIth world road congress. Brussels 13-19, Sept 1987, . (1987). Belgian roads. Innovations. Paris: PIARC. XVIIIth world road congress. Brussels 13-19.

MLA

PIARC. XVIIIth world road congress. Brussels 13-19, Sept 1987, . Belgian roads. Innovations. Paris: PIARC. XVIIIth world road congress. Brussels 13-19. 1987.