Educational Researcher 18 

 - washington  Aera central office  Dez. 1989 
 - 44 
 - 20100824 
 - Educational Researcher  18 .
<br/><br/><label>ISSN: </label>1679-656X 
<br/><br/><label>Dewey Class. No.: </label>ELR 2010  / 2010