Kerrod, R. (1997). Macmillan Encyclopedia of Science: V. 8 : Industry: Mining and manufacturing. Saint Joseph's University.
Chicago-referens (17:e uppl.)Kerrod, Robin. Macmillan Encyclopedia of Science: V. 8 : Industry: Mining and Manufacturing. Saint Joseph's University, 1997.
MLA-referens (8:e uppl.)Kerrod, Robin. Macmillan Encyclopedia of Science: V. 8 : Industry: Mining and Manufacturing. Saint Joseph's University, 1997.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.