Cruz, Corazon L. <br/><br/>
Introduction to logic / 
Corazon L. Cruz. 
 - 4th ed. 
 - Mandaluyong City :  National Bookstore,  c2004. 
 - xii, 363 p. 
<br/><br/> Includes bibliographical references and index. 
<br/><br/><label>ISBN: </label>971-08-5797-5 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Logic