Search Results       Your search for [author]Valetin, Helmut. returned 1 record.           Research report chronic bronchitis and occupational dust exposure : cross-sectional study of occupational medicine on the significance of chronic inhalative burdens for the bronchopulmonary systems. by Valetin, Helmut.; Boppard, West Germany: Boldt, 1978. Subject: Bronchitis.          Add to Book Cart Relevance: 21.96%