"Complication for simplicity's sake"
Article by Stewart Hine from 'Model Railways' November 1979

"Linked section control"
Articles by L. E. Carroll from 'Model Railway News':

• General Principles, September 1953
• Single Lines and Ovals, October 1953
• Junctions and Return Loops, December 1953

"Linked Section Control in action“
Article by L. E. Carroll from 'Model Railway News' June 1958

"Signal-box Sub-sectioning"
Article by L. E. Carroll from 'Model Railway News' June 1956