Albrecht, C.Klitzing, K.Schweizer, H.Smet, J. H.Umansky, V.Weiss, D.2004-12-102004-12-1020012001http://hdl.handle.net/2003/1802410.17877/DE290R-11859enThe American Physical SocietyPhysical Review Letters530Evidence of Hofstadters Fractal Energy Spectrum in the Quantized Hall Conductance10.1103/PhysRevLett.86.147article (journal)