Guido Zuccon Leif Azzopardi Claudia Hauff Keith van Rijsbergen Estimating interference in the QPRP for subtopic retrieval. 741-742 2010 SIGIR http://doi.acm.org/10.1145/1835449.1835593 conf/sigir/2010 db/conf/sigir/sigir2010.html#ZucconAHR10