National Research Council (U.S.). Transportation Research Board. (1992). Railroad issues. Transportation Research Board, National Research Council.
Lua i Stíl Chicago (17ú heag.)National Research Council (U.S.). Transportation Research Board. Railroad Issues. Washington, D.C: Transportation Research Board, National Research Council, 1992.
Lua MLA (9ú heag.)National Research Council (U.S.). Transportation Research Board. Railroad Issues. Transportation Research Board, National Research Council, 1992.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.