Practical Research :  Planning and Design / 
Paul D. Leedy , Jeanne ellis Ormrod  
 - 9th ed. 
 - Boston :  Pearson ,  2010. 
 - xvii,336 ; 
<br/><br/><label>ISBN: </label>9780137152421 
<br/><br/><label>LC Class. No.: </label>Q180.55  / .L43 2010