TY  - BOOK
AU  - Goettl,Barry P[et..al].
TI  - Intelligent tutoring systems
T2  - Lecture notes in computer science,No-1452
SN  - 3540647708
U1  - 004 LEC 
PY  - 1998///
CY  - Berlin
PB  - Springer
N1  - Includes bibliographical references
ER  -