The fraction of DA white dwarfs with kilo-Gauss magnetic fields S. Jordan, R. Aznar Cuadrado, R. Napiwotzki, H. M. Schmid and S. K. Solanki A&A, 462 3 (2007) 1097-1101 Published online: 21 November 2006 DOI: 10.1051/0004-6361:20066163