1. Thomson, J. J. Rays of Positive Electricity and Their Application to Chemical Analysis19131stLondonLongmans, Green & Co.19211921
2. Aston, F. W. Mass Spectra and Isotopes19331stLondonLongmans19411941
3. Soddy, F. Ann. Reports Chem. Soc.1910, 285.
4. THE ATOMIC WEIGHT OF LEAD OF RADIOACTIVE ORIGIN.