Electronic structure of YBa2Cu3O7-x by positron annihilation Hoffmann, L. ; Manuel, A. A. ; Peter, M. ; Walker, E. ; Damento, M. A. Abstract Publication: EPL (Europhysics Letters) Pub Date: May 1988 DOI: 10.1209/0295-5075/6/1/011 Bibcode: 1988EL......6...61H