TWIN RESEARCH 3 - PROCEEDINGS OF THE 3RD INTERNATIONAL-CONGRESS ON TWIN STUDIES, JUNE 16-20, 1980, IN JERUSALEM, PT A, TWIN BIOLOGY AND MULTIPLE PREGNANCY, PT B, INTELLIGENCE, PERSONALITY, AND DEVELOPMENT, PT C, EPIDEMIOLOGICAL AND CLINICAL-STUDIES - GEDDA,L, PARISI,P, NANCE,WE