Keller, Lena. <br/><br/>
Nonlinear relations between achievement and academic self-concepts in elementary and secondary school:  an integrative data analysis across 13 countries / 
Lena Killer, Franzis Preckel, and  Martin Brunner. 
 - Washington;   American Psychological Association,    April 2021. 
 - volume 113, pages 585-604,  illustration. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Psychology.<br/>Academic Achievement.<br/>Mathematics.
<br/><br/><label>Dewey Class. No.: </label>DPer 370.15 J826 April - May 2021 v113no. 3-4