Research and technical writing 
Portillo, Reynaldo R. 
 -  Trinitas Publishing, Inc.  2003 
 - 259 pages. 
<br/><br/>
<br/><br/><label>ISBN: </label>9-71420393-7 
<br/><br/><label>Dewey Class. No.: </label>F 001.42 R31 2003