References.

Percy, John, “Metallurgy (Copper).”

Gowland, William, Presidential Address, Trans. Inst. Mining and Metallurgy, vol. xvi., 1906–7, pp. 265–291.

Stevens, H. J.,“The Copper Handbook.”

Brown, N., and Turnbull, C. C., “A Century of Copper.”

Engineering and Mining Journal, “Copper Production.” May 6th, 1910, p. 891.

Mineral Statistics of the United Kingdom.

Mineral Industry.