STUDY OF DEFECTS IN a-Ge AND a-GeHx USING SURFACE ACOUSTIC WAVE TECHNIQUE K.L. Bhatia, M.v. Haumeder et S. Hunklinger J. Phys. Colloques, 42 C4 (1981) C4-365-C4-368 DOI: 10.1051/jphyscol:1981478