1. W. Maenhaut, in “Controle and Fate of Atmospheric Trace Metals,” J.M. Pacyna, B. Ottar, eds., Kluwer Academic Publishers, New York (1989).
2. A.L. Gray, in “Inorganic Mass Spectrometry”, F. Adams, R. Gijbels, R. Van Grieken, eds., Wiley, New York (1988).
3. D.L. Fox, Anal. Chem., 59:280R (1987).
4. A. Alian, B. Sansoni, J. Radioanal. Nucl. Chem., 89:191 (1985).
5. W. Maenhaut, Anal. Chim. Acta, 195:123 (1987).