TY  - BOOK
AU  - Keller, Lena.
AU  - Keller, Lena.
AU  - Preckel, Franzis.
AU  - Brunner, Martin.
TI  - Nonlinear relations between achievement and academic self-concepts in elementary and secondary school: an integrative data analysis across 13 countries 
U1  - DPer 370.15 J826 April - May 2021 v113no. 3-4 
PY  - 2021///
CY  - Washington
PB  -  American Psychological Association, 
KW  - Psychology
KW  - Academic Achievement
KW  - Mathematics
ER  -