COncepts of methods of invironment statistics of natural environment   A technical report.    

 - New York  United Nations          1991 
 - x,148p.  cm. 
<br/><br/> Studies in methods series F, no. 57 
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Dewey Class. No.: </label>X:(G):55.N91t, N1/UN