HeidelTime: High Quality Rule-Based Extraction and Normalization of Temporal Expressions Jannik Strötgen author Michael Gertz author 2010-07 text Proceedings of the 5th International Workshop on Semantic Evaluation Katrin Erk editor Carlo Strapparava editor Association for Computational Linguistics Uppsala, Sweden conference publication strotgen-gertz-2010-heideltime https://aclanthology.org/S10-1071/ 2010-07 321 324