Portillo, Reynaldo R. <br/><br/>
Research and technical writing/ 
Reynaldo R. Portillo, Imelda K. Gamboa, Vivian B. Flores, Ma. Consuelo S. Quindara, Mila E. Isles, Amelia O. Bacungan, Clarita O. Manzano and Carolina G. Alberca 
 - Bulacan:  Trinitas Publishing, Inc.,  c2003. 
 - xv, 259 pages ;  illustrations ;  25 cm. 
<br/><br/>Includes bibliographical references, index and glossary. 
<br/><br/><label>ISBN: </label>9-71420393-7 (pbk.)