1. Trace element content of the standard granite (G-l) and standard diabase (W-l);Ahrens;U.S. Geol. Survey Bull.,1960
2. Spectrochemical Analysis;Ahrens,1961
3. Tektites;Baker;Mem. Nat. Mus. Vict.,1959
4. Natural glass from Macedon, Victoria, and its relationship to other natural glasses;Baker;J. Geol.,1946
5. The abundances of gallium and germanium in terrestrial materials;Burton;Geochim. et Cosmochim. Acta,1959