== References ==* R.J. Callow, "The Industrial Chemistry of the Lanthanons, Yttrium, Thorium and Uranium", Pergamon Press, 1967* F.H.
* Ферроцерий*R.J. Callow, "The Industrial Chemistry of the Lanthanons, Yttrium, Thorium and Uranium", Pergamon Press, 1967*Gupta, C. K.; Krishnamurthy, N. (2005).