@article{weko_82615_1,
   author	 = "Kazuya,Haraguchi and Yasutaka,Abe and Akira,Maruoka",
   title	 = "How to Produce BlockSum Instances with Various Levels of Difficulty",
   journal	 = "情報処理学会論文誌",
   year 	 = "2012",
   volume	 = "53",
   number	 = "6",
   month	 = "jun"
}