Bias on Estimates of X-ray Cluster Mass E. Rasia, S. Ettori, L. Moscardini, P. Mazzotta, S. Borgani, K. Dolag, G. Tormen, L.M. Cheng and A. Diaferio EAS Publications Series, 20 (2006) 295-296 Published online: 19 May 2006 DOI: 10.1051/eas:2006097