Theory of condensed matter lectures presented at an international course organized by and held at the International Centre for Theoretical Physics, Trieste, from 3 October to 16 December, 1967 - Antonec!k, Emil; Bassanti, Giuseppe Franco, 1929-; Caglioti, Giuseppe; Ziman, J. M. (John M.), 1925- (International Atomic Energy Agency, 1968)