Provisional guidelines on standard international age classifications. 

 - New York  United Nations          1982 
 - iv,28p.  cm. 
 -  Vol. 1 .
<br/><br/> Statistics papers series M, no. 74 
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Dewey Class. No.: </label>V1N45,93:3.N82, M2/UN