| Reference | Title | Date |
| RHP10000 | National Coal Board Plans | 1938-1965 |
| RHP10000/LK545 | Plan of (1) whole coal and seams of coal and other minerals under part of the lands and estate of Douglas known as the Rigside Mineral Field. (2) The whole coal and other metals under part of the lands of Ponfeigh (3) The whole coal and seams of coal and other minerals under part of said lands and estate in Parish of Douglas | 1938 |