SR Regulations for Train Signalling on Double and Singles Lines with amendment
British Railways BR 29960 Regulations for Train Signalling 1st October 1960
Railway Book:BR-Regulations for Train Signalling and Signalmens General Duties
LONDON MIDLAND AND SCOTTISH RAILWAY REGULATIONS FOR TRAIN SIGNALLING ON DOUBLE
British Railway Regulations for Train Signalling and Signalmen's General 1972
GWR Regulations For Train Signalling on Double and Single Lines 1936 92 Pages
