You can do simple searches using this form:

Type	Originator	Title	Date
	Institute of British Geographers (Transactions No.54 (Nov), pp.89-100)	Gash Breccias of South Pembrokeshire, Fossil Karst?	1971
	Geological Magazine Vol XCI No 3 pp.220-226	Solution Subsidence Outliers of Millstone Grit on the Carboniferous Limestone of the North Crop of the South Wales Coalfield	1954
	Thomas,T.M	Solution Subsidence in S.E.Carmarthenshire & S.W.Breconshire
	RGS (Geographical Journal 120(4),pp.468-475)	Swallow Holes on the Millstone Grit and Carboniferous Limestone of the South Wales Coalfield	1954
	Thomas,T.M	The Mineral Wealth of Wales & its Exploitation
	Thomas,T.M	The Mineral Wealth of Wales and its Exploitation
	Thomas,T.M	The Mineral Wealth of Wales and its Exploitation