Ryan, John C. <br/><br/>
Life support :  conserving biological diversity / 
John C. Ryan,  
 - Washington :  Worldwatch Institute (WI) ,  1992 
 - 62p. :  ill. ;  20cm.  
 - Worldwatch paper  No. 108 .
<br/><br/>Includes bibliographical references. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Life<br/>Ecosystems
<br/><br/><label>Gov. Doc. Class. No.: </label>US WI P-108