1. A. Pais, “Radioactivity’s Two Early Puzzles,” Rev. Mod. Phys. 49 (1977), 925–938, p. 927.
2. K. Hutchison, J.A. Gray and H.S.W. Massey, “Charles Drummond Ellis,” Biog. Mem. Fel. Roy. Soc. 27 (1981), 198–233, p. 205
3. C.D. Ellis and W.A. Wooster, “The β-Ray Type of Disintegration,” Proc. Comb. Phil. Soc. 22 (1923–1925), 849–860; L. Meitner, “über die Rolle der γ-Strahlen beim Atomzerfall,” Z. Phys. 26 (1924), 169–177.
4. Ellis and Wooster, “β-Ray Type” (note 3), p. 857.
5. Ibid., p. 859.