J. Freitas et al., "Multimodal corpora for silent speech interaction", in Proc. of the Ninth Int. Conf. on Language Resources and Evaluation (LREC 2014), Nicoletta Calzolari, Khalid Choukri, Thierry Declerck, Hrafn Loftsson, Bente Maegaard, Joseph Mariani, Asuncion Moreno, Jan Odijk and Stelios Piperidis, Ed., Reykjavik, European Language Resources Association (ELRA), 2014, pp. 4507-4511