Extraterrestrials  where are they ? 
edited by Ben Zukerman and Micheal H. Hart                                             
 - 2nd ed. 
 - Cambridge  Cambridge University Press  1995 
 - xii, 239p. 
<br/><br/><label>ISBN: </label>0-521-44335-0 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Extraterrestrial life<br/>Galaxy.<br/>interstellar communication
<br/><br/><label>Universal Decimal Class. No.: </label>52-37  / EXT