Technological developments in lead and zinc production and their sig nificance production and their significance to developing countriesrepo rt /  
United Nations Industrial Development Organization. 
 - New York :    United Nations,    1970. 
 - 85 p. ;    30 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Lead and zinc production -- Developing countries.<br/> Lead and zinc industry -- Developing countries.