Magnetism of mixed valence (LaSr) hexaferrites P. Novák, K. Knížek, M. Küpferling, R. Grössinger and M. W. Pieper Eur. Phys. J. B, 43 4 (2005) 509-515 Published online: 30 March 2005 DOI: 10.1140/epjb/e2005-00084-8