Não informado. (1946). Bulletin. National Research Council, Highway Research Board.
Chicago-referens (17:e uppl.)Não informado. Bulletin. Washington: National Research Council, Highway Research Board, 1946.
MLA-referens (8:e uppl.)Não informado. Bulletin. National Research Council, Highway Research Board, 1946.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.