Weak magnetic fields in central stars of planetary nebulae? M. Steffen, S. Hubrig, H. Todt, M. Schöller, W.-R. Hamann, C. Sandin and D. Schönberner A&A, 570 (2014) A88 Published online: 22 October 2014 DOI: 10.1051/0004-6361/201423842