Mary Elvira Weeks (1932). "The discovery of the elements. X. The alkaline earth metals and magnesium and cadmium". Journal of Chemical Education9 (6): 1046. doi:10.1021/ed009p1046. Bibcode: 1932JChEd...9.1046W.
Mary Elvira Weeks (1932). "The discovery of the elements. XII. Other elements isolated with the aid of potassium and sodium: Beryllium, boron, silicon, and aluminum". Journal of Chemical Education9 (8): 1386. doi:10.1021/ed009p1386. Bibcode: 1932JChEd...9.1386W.
Mary Elvira Weeks (1933). "The discovery of the elements. XIX. The radioactive elements". Journal of Chemical Education10 (2): 79. doi:10.1021/ed010p79. Bibcode: 1933JChEd..10...79W.
harvard.edu
adsabs.harvard.edu
Mary Elvira Weeks (1932). "The discovery of the elements. X. The alkaline earth metals and magnesium and cadmium". Journal of Chemical Education9 (6): 1046. doi:10.1021/ed009p1046. Bibcode: 1932JChEd...9.1046W.
Mary Elvira Weeks (1932). "The discovery of the elements. XII. Other elements isolated with the aid of potassium and sodium: Beryllium, boron, silicon, and aluminum". Journal of Chemical Education9 (8): 1386. doi:10.1021/ed009p1386. Bibcode: 1932JChEd...9.1386W.
Mary Elvira Weeks (1933). "The discovery of the elements. XIX. The radioactive elements". Journal of Chemical Education10 (2): 79. doi:10.1021/ed010p79. Bibcode: 1933JChEd..10...79W.
lbl.gov
ie.lbl.gov
Richard B. Firestone (15 March 2010). "Isotopes of Calcium (Z=20)". Lawrence Berkeley National Laboratory. Archived from the original on 6 May 2012. பார்க்கப்பட்ட நாள் 12 June 2012.
Richard B. Firestone (15 March 2010). "Isotopes of Barium (Z=56)". Lawrence Berkeley National Laboratory. Archived from the original on 6 May 2012. பார்க்கப்பட்ட நாள் 12 June 2012.
Richard B. Firestone (15 March 2010). "Isotopes of Calcium (Z=20)". Lawrence Berkeley National Laboratory. Archived from the original on 6 May 2012. பார்க்கப்பட்ட நாள் 12 June 2012.
Richard B. Firestone (15 March 2010). "Isotopes of Barium (Z=56)". Lawrence Berkeley National Laboratory. Archived from the original on 6 May 2012. பார்க்கப்பட்ட நாள் 12 June 2012.