Technological developments in lead and zinc production and their significance to developing countries. 

 - New York :  United Nations,  1970. 
 - [United Nations. Document] ;  ID/45:ID/WG.33/19 .
 - Document (United Nations) ;  ID/45:ID/WG.33/19 .
<br/><br/> At head of title: United Nations Industrial Development Organization. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Lead industry and trade -- Congresses.--Lead industry and trade -- Congresses.<br/>Zinc industry and trade -- Congresses.--Zinc industry and trade -- Congresses.
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Developing countries -- Lead industry and trade -- Congresses.--Developing countries -- Lead industry and trade -- Congresses.--Developing countries -- Lead industry and trade -- Congresses.<br/>Developing countries -- Zinc industry and trade -- Congresses.--Developing countries -- Zinc industry and trade -- Congresses.--Developing countries -- Zinc industry and trade -- Congresses.