Discovering Latent Concepts and Exploiting Ontological Features for Semantic Text Search Vuong M Ngo author Tru H Cao author 2011-11 text Proceedings of 5th International Joint Conference on Natural Language Processing Haifeng Wang editor David Yarowsky editor Asian Federation of Natural Language Processing Chiang Mai, Thailand conference publication ngo-cao-2011-discovering https://aclanthology.org/I11-1064/ 2011-11 571 579