Natural resources and development. 

 - Turbigen :    Institute for Scientific Cooperation and Geological Su rvey,    1975- 
 - v. :    ill. ;    27 cm. 
 - Semiannual,    1975- 
 - 1975- 
<br/><br/><label>ISSN: </label>03402797 
<br/><br/><label>Dewey Class. No.: </label>PER 333.0 N 38