







Bureau of Mines, 1971.  Beryllium.  Minerals Yearbook Metals, Minerals, and Fuels, Volume 1, pages 215 - 219.  Bureau of Mines, U.S. Department of the Interior, Washington, DC.  Available online at http://digicoll.library.wisc.edu/cgi-bin/EcoNatRes/EcoNatRes-idx?id=EcoNatRes.MinYB1971v1.  Accessed February 20, 2012.

