G.R. Jones

year of pub­li­ca­ti­onISBNauthor(s)title
1998978-0-9533692-0-1Griff R. JonesHafodlas Slate Quarry, Bettws-y-Coed
2002978-0-9533692-1-8Griff R JonesThe rock cannon of Gwynedd
2005978-0-9533692-2-5   ''Rhiwbach Slate Quarry: Its History and Development