1. Intelligent Tutoring Systems,1982
2. Artificial intelligence and tutoring systems;Wenger,1987
3. Hypermidia English Learning Environment Based on Language Understanding and Error Origin Identification;Takeuchi;IEICE Trans.Inf. and Syst.,1994
4. Development of an Environmental CAI System for English Conversation Learning;Okamoto;IEICE Trans.Inf. and Syst.,1994
5. Grammars as user models;Shuster,1985