Reference | Title | Date |
RHP146000 | National Coal Board Inspectorate plans of workings | 1957- |
RHP146000/591 | Plans of workings at Ordnance Survey National Grid Reference NS 26/9293 Shawbernaig, Birkhill, No. 13 Shaft and Grassmainston Mine noted on these plans. | 1954-1958 |