TY  - BOOK
AU  - Clark,R C
AU  - Mayer,R
TI  - E-learning and the science of instruction : :  proven guidelines for consumers and designers of multimedia learning / 
SN  - 9780470874301
PY  - 2011///
CY  - San Francisco, CA : 
PB  -  Pfeiffer, 
KW  - E-learning
ER  -