Portillo, Reynaldo R. ;  <br/><br/>
Research And Technical Writing / 
Portillo, Reynaldo R. ;  
 - Manila;   Trinitas PUblishing, Inc.   [2003]; 
<br/><br/><label>ISBN: </label>9789714253938; 
<br/><br/><label>Dewey Class. No.: </label>651.7