1. Bell, R. E.: Coincidence Techniques and the Measurement of Short Mean Lives. In: Alpha-, Beta- and Gamma-Ray Spectroscopy (ed. K. Siegbahn), Vol. 2, p. 905. Amsterdam: North-Holland Publishing Company 1965.
2. de Benedetti, S., and R. W. Findley: Handbuch der Physik (ed. S. Flügge), Vol. LXV, p. 222. Berlin-Göttingen-Heidelberg: Springer 1958.
3. Miehe, J. A., E. Ostertag and A. Coche: IEEE Trans. Nucl. Sci. NS-13/3, 127 (1966).
4. Bell, R. E., H. E. Petch: Phys. Rev. 76, 1409 (1949).
5. Bell, R. E., H. E. Petch, R. L. Graham, and H. E. Petch: Canad. J. Phys. 30, 35 (1952).