Mitsuko Yamura-Takei Miho Fujiwara Makoto Yoshie Teruaki Aizawa Automatic Linguistic Analysis for Language Teachers: The Case of Zeros. 2002 COLING http://acl.ldc.upenn.edu/C/C02/C02-1051.pdf db/conf/coling/coling2002.html#Yamura-TakeiFYA02