@inproceedings{weko_408_1,
   author	 = "北村,達也 and 川村,よし子",
   title	 = "逆文献頻度と文字の難易度に基づく単語レベル判定システムの構築",
   booktitle	 = "日本語教育学会 秋季大会予稿集",
   year 	 = "2009",
   volume	 = "",
   number	 = "",
   pages	 = "287--288"
}