Fundamentals of Investigation and Intelligence / 
Donald T. Sumad . 
 - Quezon City :  Wiseman’s Book Trading,  2020. 
 - vi, 194 p.  
<br/><br/> Includes References 
<br/><br/><label>ISBN: </label>6214181582 
<br/><br/><label>Dewey Class. No.: </label>153.9 Su61 2020