M. Zhang, Y. Liu, H. Luan, und M. Sun. Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), 1, Seite 1959--1970. (2017)
V. Spitkovsky, H. Alshawi, und D. Jurafsky. NIPS 2009 Workshop on Grammar Induction, Representation of Language and Language Learning, Whistler, Canada, (Dezember 2009)