Measuring Prerequisite Relations Among Concepts Chen Liang author Zhaohui Wu author Wenyi Huang author C Lee Giles author 2015-09 text Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing Lluís Màrquez editor Chris Callison-Burch editor Jian Su editor Association for Computational Linguistics Lisbon, Portugal conference publication liang-etal-2015-measuring 10.18653/v1/D15-1193 https://aclanthology.org/D15-1193/ 2015-09 1668 1674