State of environment 

 - Washington  Conservation Foundation           1982 
 - xvi,464p. Bib chapterwise  cm. 
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geography- Environment
<br/><br/><label>Dewey Class. No.: </label>U:(G:55).73.N7, M2