APA Style
Prospects for coal mining. (9 December 1991).
:
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Chicago Style
Prospects for coal mining.
.
:
,
9 December 1991.
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MLA Style
Prospects for coal mining.
.
:
,
9 December 1991.
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Turabian Style
Prospects for coal mining.
:
,
9 December 1991.
.