1. Beta- and Gamma-Ray Spectroscopy;Siegbahn,1955
2. The Focusing of Charged Particles by a Spherical Condenser
3. Personal communication (1954) to K. Siegbahn, reported in Beta- and Gamma-Ray Spectroscopy;Allison,1955
4. Personal Communication (1954) to K. Siegbahn, reported in Beta- and Gamma-Ray Spectroscopy;Siegbahn,1955
5. Classical Mechanics;Goldstein,1951