Clark, P., Etzioni, O., Khot, T., Sabharwal, A., Tafjord, O., Turney, P. and Khashabi, D. (2016) “Combining Retrieval, Statistics, and Inference to Answer Elementary Science Questions”, Proceedings of the AAAI Conference on Artificial Intelligence, 30(1). doi: 10.1609/aaai.v30i1.10325.