Are References Really Needed? Unbabel-IST 2021 Submission for the Metrics Shared Task Ricardo Rei author Ana C Farinha author Chrysoula Zerva author Daan van Stigt author Craig Stewart author Pedro Ramos author Taisiya Glushkova author André F T Martins author Alon Lavie author 2021-11 text Proceedings of the Sixth Conference on Machine Translation Loic Barrault editor Ondrej Bojar editor Fethi Bougares editor Rajen Chatterjee editor Marta R Costa-jussa editor Christian Federmann editor Mark Fishel editor Alexander Fraser editor Markus Freitag editor Yvette Graham editor Roman Grundkiewicz editor Paco Guzman editor Barry Haddow editor Matthias Huck editor Antonio Jimeno Yepes editor Philipp Koehn editor Tom Kocmi editor Andre Martins editor Makoto Morishita editor Christof Monz editor Association for Computational Linguistics Online conference publication rei-etal-2021-references https://aclanthology.org/2021.wmt-1.111/ 2021-11 1030 1040