Gerring, John. <br/><br/>
Case Study Research :    Principles and Practices /  
John Gerring  
 - Cambrige :   Cambridge University Press,  c2017. 
 - xxix, 330p. 
<br/><br/><label>ISBN: </label>9781316632505 
<br/><br/><label>Dewey Class. No.: </label>001.433  / GER/C