Constructing Datasets for Multi-hop Reading Comprehension Across Documents Johannes Welbl author Pontus Stenetorp author Sebastian Riedel author 2018 text journal article Transactions of the Association for Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal welbl-etal-2018-constructing 10.1162/tacl_a_00021 https://aclanthology.org/Q18-1021/ 2018 6 287 302