Não informado. (1977). American transportation builder. American Road Builders Association.
Chicago-referens (17:e uppl.)Não informado. American Transportation Builder. Washington: American Road Builders Association, 1977.
MLA-referens (8:e uppl.)Não informado. American Transportation Builder. American Road Builders Association, 1977.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.