APA

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

Chicago

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

Harvard

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

MLA

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