Dyddiadur,
Dyddiadur,
Penrhyn Quarry rules and minutes
Penrhyn Quarry rules and minutes
Gwaith W. J. Parry,
Gwaith W. J. Parry,
Letters and papers of D. R. Daniel
Letters and papers of D. R. Daniel
Penrhyn quarry,
Penrhyn quarry,
The Slate Industry of North Wales: the Quarrymen's Union
The Slate Industry of North Wales: the Quarrymen's Union
Letters, &c.,
Letters, &c.,
