Word population monitoring  : 1991 : with special emphasis on age structure 
/ Nations unies 
. - New York  : United Nations, 1992
. - XII-241 p.  ; 28 cm. 
 - Population studies  126 .
<br/><br/><label>ISBN: </label>9211512409 
<br/><br/><label>Universal Decimal Class. No.: </label>312.