Purtill , Richard L <br/><br/>
Logical thinking / 
Richard L. Purtill 
 - New York :  Haper & row,  1972 
 - 157p. ;  17 cm 
<br/><br/><label>Subjects--Topical Terms: </label><br/>	 Logic<br/> Logisches Denken.<br/> Logic -- Problems,
<br/><br/><label>Dewey Class. No.: </label>160  / PUL 1972