Precision mass measurements of 40Ca17+ and 40Ca19+ ions in a Penning trap Sz. Nagy, T. Fritioff, A. Solders, R. Schuch, M. Björkhage and I. Bergström Eur. Phys. J. D, 39 1 (2006) 1-4 Published online: 28 March 2006 DOI: 10.1140/epjd/e2006-00064-8