Zinc Mine at Willyhole Mine (Lower), Forest and Frith - Source of Reference
| No. | Originator(s) | Date | Title | Notes |
|---|---|---|---|---|
| 1 | Wilcock, D | 1996 to 1998 | IRIS (Index Record for Industrial Sites) Survey Archive | DU/DACE/83040 |
| 2 | Wilcock, D | 1997 | Personal Comment by Don Wilcock 1997 | |
| 3 | Ordnance Survey | 1856 to 1865 | First Edition Ordnance Survey Map | 6", Durham 30, 1861 |
| 4 | Dunham, K C | 1990 | The Geology of the Northern Pennine Orefield, Volume 1 TYNE to STAINMORE | p. 241, 231 |
| 5 | English Heritage | 1993 | The Zinc Industry, North Yorks Step 3 Report | 1b |
| 6 | Newcastle City Archaeology Unit, Truman, L | 01-Jan-1994 to 31-Dec-1994 | RCHME: North Pennines Industrial Archaeology Project | |
| 7 | Ordnance Survey | 1894 to 1899 | Second Edition Ordnance Survey Map | Durham 30 NW, 1899 |
| 8 | 1951 to 1959 | Fifth Epoch Ordnance Survey Map | 6" 1954 |