Não informado. (2011). Railway Signaling and Communications. Simmons Boardman Publishing.
Lua i Stíl Chicago (17ú heag.)Não informado. Railway Signaling and Communications. Chicago, Ill: Simmons Boardman Publishing, 2011.
Lua MLA (8ú heag.)Não informado. Railway Signaling and Communications. Simmons Boardman Publishing, 2011.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.