Delocalization in disordered chains with random symmetrical impurities X. Q. Huang, R. W. Peng, F. Qiu, S. S. Jiang and A. Hu Eur. Phys. J. B, 23 3 (2001) 275-281 Published online: 15 October 2001 DOI: 10.1007/s100510170046