6Feng Wang, Jie Qiu, Jie Yang, et al. Hadoop High availability through metadata replication. In: Proceeding of the First International Workshop on Cloud Data Management. Hong Kong, China. Nov. 2009.
7ERICKSON J S, SPENCE S, RHODES M, et al. Content - Centered Collaboration Spaces in the Cloud [ J]. IEEE Internet Computing 2009, 13(5).