1. H. Frauenfelder and R.M. Steffen, in Alpha-, Beta-and Gamma-Ray Spectroscopy (ed. K. Siegbahn, North-Holland Publ. Co., Amsterdam 1965).
2. M.L.J. Yates, in Perturbed Angular Correlations (ed. E. Karlsson, E. Matthias and K. Siegbahn, North-Holland Publ. Co., Amsterdam, 1964).
3. A.M. Feingold and S. Frankel, Phys. Rev. 97 (1955) 1025.
4. D.C. Camp and A.L. van Lehn, Nucl. Instr. and Methods 76 (1969) 192.
5. D.E. Raeside and M.L. Wiedenbeck, Nucl. Instr. and Methods 78 (1970) 331.