Effective Selectional Restrictions for Unsupervised Relation Extraction Alan Akbik author Larysa Visengeriyeva author Johannes Kirschnick author Alexander Löser author 2013-10 text Proceedings of the Sixth International Joint Conference on Natural Language Processing Ruslan Mitkov editor Jong C Park editor Asian Federation of Natural Language Processing Nagoya, Japan conference publication akbik-etal-2013-effective https://aclanthology.org/I13-1187/ 2013-10 1312 1320