Manipulating the Difficulty of C-Tests Ji-Ung Lee author Erik Schwan author Christian M Meyer author 2019-07 text Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics Anna Korhonen editor David Traum editor Lluís Màrquez editor Association for Computational Linguistics Florence, Italy conference publication lee-etal-2019-manipulating 10.18653/v1/P19-1035 https://aclanthology.org/P19-1035/ 2019-07 360 370