Seiffert, Helmut <br/><br/>
Introduccion a la logica  propedeutica logica y logica formal 
Helmut Seiffert ; tr. Diorki 
 - Barcelona  Herder  1977. 
 - 290 p.  illus.  22 cm. 
<br/><br/> Translated from : Einfuhrung in die Logik. 
<br/><br/>Includes bibliography. 
<br/><br/><label>ISBN: </label>842540648X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Logic<br/>Logic, Symbolic and mathematical