Pit/underground working.***
Publications (4)
- Richards, Alun J. (2004); Slate Quarrying at Corris; pp.124; Gwasg Carreg Gwalch; ISBN 1-84524-068-5
- Richards, Alun J. (2013); Slate Quarrying in Wales; Gwasg Carreg Gwalch; ISBN 1-84527-026-6
- Richards, Alun John (1991); Gazeteer of the Welsh Slate Industry, A; Gwasg Carreg Gwalch 978-0863811968
- Richards, Alun John, (1999); The Slate Regions of North and Mid Wales and their Railways; Gwasg Carreg Gwalch; 0863815738
