APA
PIARC. Permanent International Association of Road Congresses, . (1977). World road congress. 15. Mexico, 1975. Report of the proceedings. London: PIARC. Permanent International Association of Road Congresses.
Chicago
PIARC. Permanent International Association of Road Congresses, . 1977. World road congress. 15. Mexico, 1975. Report of the proceedings. London: PIARC. Permanent International Association of Road Congresses.
Harvard
PIARC. Permanent International Association of Road Congresses, . (1977). World road congress. 15. Mexico, 1975. Report of the proceedings. London: PIARC. Permanent International Association of Road Congresses.
MLA
PIARC. Permanent International Association of Road Congresses, . World road congress. 15. Mexico, 1975. Report of the proceedings. London: PIARC. Permanent International Association of Road Congresses. 1977.