GIST-IT: Combining Linguistic and Machine Learning Techniques for Email Summarization Evelyne Tzoukermann author Smaranda Muresan author Judith L Klavans author 2001 text Proceedings of the ACL 2001 Workshop on Human Language Technology and Knowledge Management conference publication tzoukermann-etal-2001-gist https://aclanthology.org/W01-1011/ 2001