R-VGAE: Relational-variational Graph Autoencoder for Unsupervised Prerequisite Chain Learning Irene Li author Alexander Fabbri author Swapnil Hingmire author Dragomir Radev author 2020-12 text Proceedings of the 28th International Conference on Computational Linguistics Donia Scott editor Nuria Bel editor Chengqing Zong editor International Committee on Computational Linguistics Barcelona, Spain (Online) conference publication li-etal-2020-r 10.18653/v1/2020.coling-main.99 https://aclanthology.org/2020.coling-main.99/ 2020-12 1147 1157