Não informado. (2000). United Kingdom mineral statistics. British Geological Survey.
Chicagoスタイル(17版)引用形式Não informado. United Kingdom Mineral Statistics. London: British Geological Survey, 2000.
MLA(8版)引用形式Não informado. United Kingdom Mineral Statistics. British Geological Survey, 2000.
警告: この引用は必ずしも正確ではありません.