@article{weko_13074_1,
   author	 = "Shaoying,Liu and AJeff.Offutt and Mitsuru,Ohba and Keijiro,Araki",
   title	 = "The SOFL Approach : An Improved Principle for Requirements Analysis",
   journal	 = "情報処理学会論文誌",
   year 	 = "1998",
   volume	 = "39",
   number	 = "6",
   pages	 = "1973--1989",
   month	 = "jun"
}