MEASUREMENTS OF THE MEISSNER-OCHSENFELD EFFECT OF HIGH-TEMPERATURE SUPERCONDUCTORS BY MEANS OF FREE-RADICAL EPR Z. Frait, D. Fraitová et L. Pust J. Phys. Colloques, 49 C8 (1988) C8-2235-C8-2236 DOI: 10.1051/jphyscol:198881001