CASSIDY, S. M. (1973). Elements of pratical coal mining. The American Institute of mining Metallurgy and petroleum engineers.
Chicago-referens (17:e uppl.)CASSIDY, Samuel M. Elements of Pratical Coal Mining. The American Institute of mining Metallurgy and petroleum engineers, 1973.
MLA-referens (8:e uppl.)CASSIDY, Samuel M. Elements of Pratical Coal Mining. The American Institute of mining Metallurgy and petroleum engineers, 1973.
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