Não informado. (2011). Railway Signaling and Communications. Simmons Boardman Publishing.
Chicago-viite (17. p.)Não informado. Railway Signaling and Communications. Chicago, Ill: Simmons Boardman Publishing, 2011.
MLA-viite (8. p.)Não informado. Railway Signaling and Communications. Simmons Boardman Publishing, 2011.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.