1. Ahrens, L. H.: Evidence of geological age against decay of Sn-115 to In-115 by electron capture. Nature 162, 413 (1948).
2. Ahrens, L. H., Taylor, S. R.: Spectrochemical Analysis, 2nd ed. Reading, Massachusetts: Addison- Wesley Publishing Co., Inc. 1961.
3. Akaiwa, H.: Abundances of selenium, tellurium, and indium in meteorites. J. Geophys. Res. 71, 1919 (1966).
4. Aller, L. H.: The Abundance of the Elements. New York: Interscience Publishers, Inc. 1961.
5. Aller, L. H.: The abundance of elements in the solar atmosphere. Advances in Astronomy and Astro physics. New York: Academic Press 1965.