1. Quantitative spectrochemical examination of the minor constituents in pollucite;Ahrens;Amer. Min.,1945
2. Geochemical studies on some of the rarer elements in South African rocks and minerals; II The geochemical relationship of thallium and rubidium in minerals of igneous origin;Ahrens;Trans. Geol. Soc. S. Africa,1945
3. Geochemical studies of some of the rarer elements in South African minerals and rocks; I Lithium in mica and feldspar;Ahrens;Trans. Geol. Soc. S. Africa,1945
4. Association of rubidium and potassium and their abundance in common igneous rocks and meteorites;Ahrens;Geochim. et Cosmochim. Acta,1952
5. Eocene anauxite clays and sands in the Coast Range of California;Allen;Geol. Soc. Amer. Bull.,1941