@techreport{weko_85809_1,
   author	 = "Chen,Qiaoyun and Zhao,Liang",
   title	 = "Approximation algorithms for the <i>L</i>-distance vertex cover problem",
   year 	 = "2012",
   institution	 = "Graduate School of Informatics, Kyoto University, Graduate School of Informatics, Kyoto University",
   number	 = "5",
   month	 = "sep"
}