Magnetic hysteresis in the microwave surface resistance of Nb samples in the critical state M. Bonura, A. Agliolo Gallitto and M. Li Vigni Eur. Phys. J. B, 53 3 (2006) 315-322 Published online: 18 October 2006 DOI: 10.1140/epjb/e2006-00381-8