Não informado. (1937). Concrete for railways. Portland Cement Association.
Lua i Stíl Chicago (17ú heag.)Não informado. Concrete for Railways. Chicago, Ill: Portland Cement Association, 1937.
Lua MLA (8ú heag.)Não informado. Concrete for Railways. Portland Cement Association, 1937.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.