Scientific and technical information for developing countries 
/ National Academy of Sciences 
 - Washington D C:   National Academy of Sciences,    1972 
 - 79p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science
<br/><br/><label>Subjects--Index Terms: </label>Geology 
<br/><br/><label>Universal Decimal Class. No.: </label>R 5/6:002(1-773)(04)  / L2