Twitchell, K.S.
Saudi Arabia, with an account of the development of its natural resources / by K.S. Twitchell, with the collaboration of Edward J. Jurji
Princeton University Press, 1953
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Twitcheil, K.S.
Saudi Arabia with an account of the development of its natural resources with the collaboration of and
New Jersey Princeton Univ. 1958
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Mining : Natural Resources Development
Artikel Jurnal
Natural resources and development
Federal Republic of Germany, 1977
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Australia : its resources and development
edited by G.L. Wood
Macmillan, 1954
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