Hydrogen spectroscopy with a Lamb-shift polarimeter - An alternative approach towards anti-hydrogen spectroscopy experimentsM. P. Westig, R. Engels, K. Grigoryev, M. Mikirtytchiants, F. Rathmann, H. Paetz gen. Schieck, G. Schug, A. Vasilyev and H. StröherEur. Phys. J. D, 57 1 (2010) 27-32DOI: https://doi.org/10.1140/epjd/e2010-00016-9