Casgliadau Arlein
Amgueddfa Cymru
Chwilio Uwch
Reciprocating Air Compressors (Surface and Underground) (booklet)
National Coal Board (Production) Codes and Rules. Revised edition. 35 page booklet in blue covers.
Nid yw sylwadau ar gael ar hyn o bryd. Ymddiheuriadau am yr anghyfleustra.