Robuta

https://www.ciaaw.org/ IUPAC Commission on Isotopic Abundances and Atomic Weights The world authority on the atomic weights of chemical elements isotopic abundances iupac commission atomic weights https://www.aanda.org/articles/aa/olm/2013/09/aa22057-13/aa22057-13.html Hot subdwarf stars in close-up view - IV. Helium abundances and the 3He isotopic anomaly of...