Clearman, Brian2009-03-272009-03-272009https://hdl.handle.net/1794/88872nd ed. 454 p.en-USRailroads -- Signaling -- DatabasesTransportation-Markings Database: Railway Signals, Signs, Marks, MarkersTransportation Markings Database: Additional Studies: Railway Signals, Signs, Marks & MarkersRailway Signals, Signs, Marks, MarkersBook