@article {DBLP:journals/corr/abs-0906-4927,
	title = {{F}ast {P}robabilistic {R}anking under x-{R}elation {M}odel},
	journal = {CoRR},
	volume = {abs/0906.4927},
	year = {2009},
	author = {Chang, Lijun and Yu, Jeffrey Xu and Qin, Lu}
}
