@misc {IOPORT.70644465,
    author       = {Xu, Jinxi and Croft, W. Bruce},
    title        = {Cluster-based language models for distributed retrieval},
    howpublished = {SIGIR, 254-261 (1999).},
    year         = {1999},
    doi          = {10.1145/312624.312687},
    identifier   = {70644465},
}