Roger Perman Yue Ma , James Mc Gilvrey <br/>
Natural Research and Environmental Economics 
Roger Perman Yue Ma , James Mc Gilvrey 
 - London  Longman  1996 
 - 6019 p. 
<br/><br/><label>ISBN: </label>0-582-2572-71 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Economics<br/>Economics