Information services on research in progress :  a worldwide inventory / 
ed. by the Smithsonian Science Information Exchange. 
 - París :  UNESCO,  1982. 
 - 320 p. 
<br/><br/><label>ISBN: </label>9231020714 
<br/><br/><label>No. de Clasificación Universal Decimal: </label>OC 058.7: 002.6: 061.6 (100) =20 INF.