|
UK | |
| MQP Ltd |
| www.virtualmicroscope.org (n.d.) http://www.virtualmicroscope.org/content/spotted-dolerite-preseli-hills |
| Cotterell, T. F., Green, D. I., Hubbard, N., Mason, J. S., Starkey, R. E., Tindle, A. G. (2011) The Mineralogy of Dolyhir Quarry, Old Radnor, Powys, Wales. UK Journal of Mines and Minerals 32, 5-61 |