TY  - BOOK
AU  - Davis, Robert H.
AU  - Yelon, Stephen L.
AU  - Alexander, Lawrence T.
TI  - Learning system design: an approach to the inprovement of instruction
SN  - 0-07-074334-7
U1  - 371.3 
PY  - 1974///
CY  - New York
PB  - McGraw Hill
ER  -