Description of the ecoregions of the United States / 
compiled by Robert G. Bailey. 
 - Washington:  U.S. Dept. of Agriculture,  1978. 
 - iv, 77 p. :  ill, maps. ;  23 cm. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ecology--United States.<br/>Ecological regions--United States.<br/>Biotic communities--United States.
<br/><br/><label>Dewey Class. No.: </label>577.0973