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Anna Nedoluzhko, Michal Novák, Martin Popel, Zdeněk Žabokrtský, Daniel Zeman (2021): Is one head enough? Mention heads in coreference annotations compared with UD-style heads. In: Proceedings of the Sixth International Conference on Dependency Linguistics (Depling, SyntaxFest 2021), pp. 101-114, Association for Computational Linguistics, Stroudsburg, PA, USA, ISBN 978-1-955917-14-8 (pdf, local PDF, bibtex)