Não informado. (1922). American highways. American Association of Highway Officials.
Chicago-referens (17:e uppl.)Não informado. American Highways. Washington: American Association of Highway Officials, 1922.
MLA-referens (8:e uppl.)Não informado. American Highways. American Association of Highway Officials, 1922.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.