Hughes G E <br/><br/>
Introduction to modal logic. 

 - London  Methuen and Co Ltd.      1968 
 - x,386p.  cm. 
<br/><br/><label>Standard No.: </label>45900 
<br/><br/><label>Source: </label> Textual 
<br/><br/><label>Dewey Class. No.: </label>R193, K8