The backup 2-center and backup 2-median problems on trees

Wang, Hung-LungHung-LungWangWu, Bang YeBang YeWuChao, Kun-MaoKun-MaoChaoKUN-MA0 CHAO2018-09-102018-09-102009http://www.scopus.com/inward/record.url?eid=2-s2.0-61349092244&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/348867application/pdf168153 bytesapplication/pdfThe backup 2-center and backup 2-median problems on treesjournal article10.1002/net.20261