Chert from Ashford in the Water, Derbyshire Dales District, Derbyshire, England, UK
UK | |
| Ford, T., Sarjeant, A., Smith, M. (1993) The minerals of the Peak district of Derbyshire. UK Journal of Mines and Minerals 13, Rockbottom Publications. 16-55 |
Bowering, G., and Flindall, R. (1998): Bulletin of the Peak District Mines Historical Society 13(5), 1-31 |