Lewis, Harry R. <br/><br/>
Unsolvable classes of quantificational formulas / 
Harry R. Lewis 
 - Reading, Mass. :  Addison-Wesley,  1979 
 - xv, 198 p. :  ill. ;  24 cm. 
<br/><br/> 'Advanced Book Program.'  Includes indexes. 
<br/><br/>Bibliography: p. 190-194. 
<br/><br/><label>ISBN: </label>0201040697 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Unsolvability (Mathematical logic)<br/>Combinatorial analysis<br/>Computable functions