1. Banarescu, L., et al.: Abstract meaning representation for sembanking. In: Proceedings of the 7th Linguistic Annotation Workshop and Interoperability with Discourse, pp. 178–186. ACL, Sofia (2013)
2. Banarescu, L., et al.: Abstract meaning representation (AMR) 1.2 specification. Technical report, Information Science Institute, University of Southern California, CA, USA (2014)
3. Koller, A.: Semantic construction with graph grammars. In: Proceedings of the 14th International Conference on Computational Semantics (IWCS), London (2015)
4. Quernheim, D., Knight, K.: DAGGER: a toolkit for automata on directed acyclic graphs. In: Proceedings of the 10th International Workshop Finite-State Methods and Natural Language Processing, pp. 40–44. ACL (2012)
5. Brainerd, W.S.: The minimalization of tree automata. Inf. Control 13(5), 484–491 (1968)