ULTRASONIC SURFACE WAVE ATTENUATION BY INDUCED SUPERCONDUCTIVITY IN PbCu AND PbAg "SANDWICHES" J.G. Park, P. Tai et S. Freake J. Phys. Colloques, 39 C6 (1978) C6-681-C6-682 DOI: 10.1051/jphyscol:19786304