Gaya APA
Lewis, Robert S. (1941).
Elements of mining (ed 2).
London:
Jhon Wiley & Sons.
Gaya Chicago
Lewis, Robert S.
Elements of mining.
ed 2
London:
Jhon Wiley & Sons,
1941.
Text.
Gaya MLA
Lewis, Robert S.
Elements of mining.
ed 2
London:
Jhon Wiley & Sons,
1941.
Text.
Gaya Turabian
Lewis, Robert S.
Elements of mining.
ed 2
London:
Jhon Wiley & Sons,
1941.
Print.