Manabu Nakamura Noriyuki Iwane Setsuko Otsuki Intelligent tutoring system for reading mathematical expressions. 56-64 2000 31 Systems and Computers in Japan 10 http://dx.doi.org/10.1002/1520-684X(200009)31:10<56::AID-SCJ6>3.0.CO;2-S db/journals/scjapan/scjapan31.html#NakamuraIO00