[83]. Ospina, T.: Paper read before second Pan-American Congr., Jan. 3, 1916.
[84]. White, R. W.: Eng. and Min. Journ., 1897, 63, p. 189.
[85]. Castillo, J. C.: Min. and Sci. Press, 1909, 98.
[86]. “Platinum-seeking in Colombia,” The Times, Nov. 26, 1912.
[87]. Mining Journ., Nov. 30, 1918, p. 700.
[88]. Millar and Singewald: Mineral Deposits of South America, New York, 1919, p. 405.
[89]. Kunz, George F.: “Platinum and Palladium in Brazil,” Pan-American Bull., April 1919, p. 408.
[90]. U.S. Comm. Repts., 1919, No. 21, p. 387.
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