Annual editions :  environment / 
John L. Allen, editor. 
 - Twentieth edition. 
 - Connecticut :  McGraw-Hill/Dushkin,  2001. 
 - x, 229 pages :  illustrations ;  28 cm. 
<br/><br/>Includes index. 
<br/><br/><label>ISBN: </label>0072433590 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Environment Periodicals. <br/>Ecology Periodicals. 
<br/><br/><label>LC Class. No.: </label>TD 172 A56 2001 CIRC