Research methodology in the life, behavioural and social sciences 
<label>;</label> Ader, Herman J. <label>;</label> Mellenbergh, Gideon J. 
 - London  Sage Pub.  1999 
 - xvii, 393p.  23 cm. 
<br/><br/><label>ISBN: </label>0761958843 
<br/><br/><label>Dewey Class. No.: </label>300.72  / RES