André F. T. Martins Julia Kreutzer Learning What's Easy: Fully Differentiable Neural Easy-First Taggers. 349-362 2017 EMNLP https://doi.org/10.18653/v1/d17-1036 https://aclanthology.org/D17-1036/ conf/emnlp/2017 db/conf/emnlp/emnlp2017.html#MartinsK17