Reference | Title | Date |
RHP146000 | National Coal Board Inspectorate plans of workings | 1957- |
RHP146000/873 | Plans of workings at Ordnance Survey National Grid Reference NT 36/3667 Fordel Mains Colliery, Easter Cowden, Southfield, Cowden Bog Wood and Easterlees Mine named on these plans. | 1964-1965 |