Chellas, Brian F <br/><br/>
Modal Logic   An Introduction 

 - New York  Cambridge University  1995 
 - 295p 
<br/><br/> includes index and biblioraphy 
<br/><br/><label>ISBN: </label>0521295157     100 
<br/><br/><label>Dewey Class. No.: </label>N14  / C418