| pubmed-article:10587326 | pubmed:abstractText | Four cross-sectional general population surveys in Italy: northern rural Po Delta area (1980-1982, n = 3284; 1988-1991, n = 2841), and central urban Pisa area (1985-1988, n = 3865; 1991-1993, n = 2841). | lld:pubmed |
