1. A. I. Ahearn (ed.), Trace Analysis by Mass-Spectrometry. New York: Academic Press. 1975. p. 272.
2. J. Franzen and K. D. Schuy, Advan. Mass-Spectry.4, 449 (1968).
3. D. B. Kormilitzy, Dissertation, Moscow, 1973.
4. K. Yanagihara, S. Sato, M. Ito, and T. Adachi, J. Iron Steel Inst. Japan6 I, 347 (1975).
5. K. Yanagihara, S. Sato, S. Oda, and H. Kamada, Analyt. Chim. Acta98, 307 (1978).