Sagan, Dorion <br/><br/>
Biospheres :  metamorphosis of planet earth / 
Dorion Sagan 
 - New York, NY :  Penguin Group ,  1990 
 - vii, 198 p. ;  24 cm. 
<br/><br/> Includes index 
<br/><br/>Bibliography: p.185-193 
<br/><br/><label>ISBN: </label>9780140193152 0140193154 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Biosphere