State of transboundary air pollution   1989 update    

 - New York  United Nation U S A       1990 
 - 86p.  cm. 
 -  1990 .
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Computer Science
<br/><br/><label>Dewey Class. No.: </label>D854.1.N8, M6;N0