Extraterrestrials :  where are they? / 
edited by Ben Zuckerman and Michael H. Hart 
 - 2nd ed 
 - Cambridge :  Cambridge University Press,  1995 . 
 - xii, 239 p. :  24 cm 
<br/><br/> Previous ed.: New York : Pergamon, 1982 
<br/><br/>Includes bibliographical references 
<br/><br/><label>ISBN: </label>0521448034  0521443350 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Life on other planets--Congresses<br/>Life--Origin--Congresses
<br/><br/><label>LC Class. No.: </label>QB54