TY  - BOOK
AU  - Hattie, John A. C. 
TI  - Visible learning : : a synthesis of over 800 meta- analyses  relation to achievement 
SN  - 978041547188
U1  - 370.1523 
PY  - 2009///
CY  - London
PB  - Routledge
KW  - Learning - Longitudinal studies
KW  - Teaching - Longitudinal studies
KW  - Effective teaching - Longitudinal studies
ER  -