Hughes, G. E. <br/><br/>
An introduction to modal logic 
[by] G. E. Hughes [and] M. J. Cresswell. 
 - London  Methuen  1968. 
 - iii-xii, 388 p.  illus.  23 cm. 
<br/><br/>Bibliography: p. 356-371. 
<br/><br/><label>LCCN: </label>76364635 //r86 
<br/><br/><label>Nat. Bib. No.: </label>B68-24982 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Modality Logic
<br/><br/><label>LC Class. No.: </label>BC199.M6  / H8 
<br/><br/><label>Dewey Class. No.: </label>160