THE PHONON SPECTROSCOPY OF DOPED MAGNESIUM OXIDE USING SUPERCONDUCTING TUNNEL JUNCTIONS F.Hasan, P.J. King, D. Murphy et V.W. Rampton J. Phys. Colloques, 39 C6 (1978) C6-993-C6-994 DOI: 10.1051/jphyscol:19786439