Chunyi Peng Minkyong Kim Zhe Zhang Hui Lei VDN: Virtual machine image distribution network for cloud data centers. 181-189 2012 INFOCOM http://dx.doi.org/10.1109/INFCOM.2012.6195556 conf/infocom/2012 db/conf/infocom/infocom2012.html#PengKZL12