Columbia subject headings:
Harvard subject headings:
Copper mines and mining--Early works to 1800.
Copper mines and mining--England--Cardiganshire.
Lead mines and mining--Early works to 1800.
Lead mines and mining--England--Cardiganshire.
Silver mines and mining--Early works to 1800.
Silver mines and mining--England--Cardiganshire.
Princeton subject headings:
Mackworth, Humphrey, Sir, 1657-1727.
Mines and mineral resources--Wales--Cardiganshire--Early works to 1800.
Pryse, Carbery, Sir, -1695.