Não informado. (1937). Concrete for railways. Portland Cement Association.
Chicago-referens (17:e uppl.)Não informado. Concrete for Railways. Chicago, Ill: Portland Cement Association, 1937.
MLA-referens (8:e uppl.)Não informado. Concrete for Railways. Portland Cement Association, 1937.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.