| Year | 1920 |
| Date | 30-Sep |
| Volume | 43 |
| Issue | 1,014 |
| Page | 267 |
| Category | Railway |
| Part | |
| Title | Railway Signalling Systems |
| Author | F.Raynar Wilson |
| Notes | Victorian Government Railways. Chapter 12. - Low Pressure Pneumatic Power Plant. Locking frame, signal movement, semi-automatic signal, point movement, locking of a frame |