Input Design in Interactive Learning Environment T-Algebra. - Marina Issakova; Dmitri Lepp; Rein Prank (ICALT, 2005)

Designing Next-Generation Training and Testing Environment for Expression Manipulation. - Rein Prank; Marina Issakova; Dmitri Lepp; Vahur Vaiksaar (International Conference on Computational Science (1), 2006)

Error Diagnosis in Problem Solving Environment Using Action-Object-Input Scheme. - Dmitri Lepp (Intelligent Tutoring Systems, 2006)

Tools for Acquiring Data about Student Work in Interactive Learning Environment T-Algebra. - Rein Prank; Dmitri Lepp (Intelligent Tutoring Systems (2), 2010)