Rapid variability of accretion in AM Herculis D. de Martino, G. Matt, B. T. Gänsicke, R. Silvotti, J. M. Bonnet-Bidaud and M. Mouchet A&A, 396 1 (2002) 213-217 Published online: 22 November 2002 DOI: 10.1051/0004-6361:20021405