Hot subdwarf stars in close-up view-IV. Helium abundances and the 3He isotopic anomaly of subdwarf B stars
Journal article published in 2013 by
S. Geier,
U. Heber,
H. Edelmann,
L. Morales-Rueda,
D. Kilkenny,
D. O’Donoghue,
Tr Marsh,
C. Copperwheat 
