CONF Mahdabi_NLDB2016_2016/IDIAP Comparing Two Strategies for Query Expansion in a News Monitoring System Mahdabi, Parvaz Popescu-Belis, Andrei Natural Language Processing and Information Systems: 21st International Conference on Applications of Natural Language to Information Systems, NLDB 2016 Lecture Notes in Computer Science 9612 267-275 2016 Springer-Verlag 10.1007/978-3-319-41754-7_24 doi