K. Boyer, E. Ha, R. Phillips, M. Wallis, M. Vouk, и J. Lester. Proceedings of the Fourth Workshop on Innovative Use of NLP for Building Educational Applications, стр. 19--26. Stroudsburg, PA, USA, Association for Computational Linguistics, (2009)
P. Woodland, J. Odell, V. Valtchev, и S. Young. Proceedings of the 1994 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2, стр. 125-128. Adelaide, Australia, (апреля 1994)