Tom Crecelius Mouna Kacimi Sebastian Michel Thomas Neumann 0001 Josiane Xavier Parreira Ralf Schenkel Gerhard Weikum Social recommendations at work. 884 2008 SIGIR http://doi.acm.org/10.1145/1390334.1390558 conf/sigir/2008 db/conf/sigir/sigir2008.html#CreceliusKMNPSW08