@techreport{weko_198155_1,
   author	 = "Peter,Spalthoff and Rio,Yokota",
   title	 = "Flexible and Simplistic Hierarchical Matrix-Based Fast Direct Solver",
   year 	 = "2019",
   institution	 = "Tokyo Institute of Technology, Presently with Tokyo Institute of Technology／Global Scientific Information and Computing Center",
   number	 = "18",
   month	 = "jul"
}