Gualdo, Rosendo S.,  c2000. <br/><br/>
Logic :  The Basics of Correct Reasoning / 
Gualdo, Rosendo S. 
 - Valenzuela City, Philippines :  Mutya Publishing House,  c2000. 
 - 156 p. :  glossary ;  10 inch. 
<br/><br/><label>ISBN: </label>971-821-004-0