Cohen , L. <br/><br/>
Research methods in education. 

 - 3rd. 
 - London :  Routledge,  1989. 
 - xxii, 413p.: ill. 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0415044103 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Research methods.