| Year | 1988 |
| Date | 16-Sep |
| Volume | 161 |
| Issue | 3,833 |
| Page | 351 |
| Category | Railway |
| Part | 2 |
| Title | Making Tracks. The Design, Construction and Maintenance of Ground Level Miniature Railways |
| Author | Dennis Monk |
| Notes | Fill for embankments, the earthworks, the formation, purpose of ballast, spreading the load, maintaining stability, drainage, size and type of ballast |