Laure Berti-Equille Anish Das Sarma Xin Dong Amélie Marian Divesh Srivastava Sailing the Information Ocean with Awareness of Currents: Discovery and Application of Source Dependence http://arxiv.org/abs/0909.1776 2009 CoRR abs/0909.1776 db/journals/corr/corr0909.html#abs-0909-1776 informal publication