Langer, Susanne K. <br/><br/>
An introduction to symbolic logic  

 - 3a. ed. rev. 
 - New York  : Dover Publications Inc.  , 1967 
 - 367 p. 
<br/><br/><label>ISBN: </label>0-486-60164-1 
<br/><br/><label>Subjects--Topical Terms: </label><br/>LÓGICA
<br/><br/><label>Dewey Class. No.: </label>511.3