1. H.H. Loosli, H. Oeschger: Earth Planet. Sci. Lett.7, 67 (1969)
2. V.V. Kuzminov, A.A. Pomansky: In Proc.18th Int'l Cosmic Ray Conf., Bangalore, Vol. 2 (1983) p. 357
3. B.E. Lehmann, H.H. Loosli: Inst. Phys. Conf. Ser.71, 219 (1984)
4. W.M. Smethie, G. Mathieu: Marine Chem.18, 17 (1986)
5. K. Rozanski, T. Florkowski: IAEA Proc.2, 949 (1979)