Chen, H. Y.Gao, H. J.Hou, S. M.Sohlberg, K.Xue, Z. Q.2004-12-032004-12-0320012001http://hdl.handle.net/2003/143610.17877/DE290R-11246enThe American Physical SocietyPhysical Review Letters53010.1103/PhysRevLett.87.179707article (journal)