1. Aulinger, F.: Z. Anal. Chem.221, 70 (1966).
2. Davis, W. D., and H. C.Miller: Gen. Elec. Techn. Inf. Ser., Report No. 65-C-050 (1965).
3. Dempster, A. J.: Report MDDC-370 (1946), U.S.Dept. of Commerce.
4. Franzen, J., K. H. Maurer u.K. D. Schuy: Z. Naturforsch.21a, 37 (1966).
5. Franzen, J., and K. D.Schuy: VII. Intern. Conf. Phenom. in Ionized Gases, Belgrade 1965.