Freitas, J., Teixeira, A., Vaz, F. & Dias, J. (2012). Automatic speech recognition based on ultrasonic doppler sensing for European Portuguese. In Doroteo Torre Toledano, Alfonso Ortega Giménez , António Teixeira, Joaquín González Rodríguez, Luis Hernández Gómez, Rubén San Segundo Hernández, Daniel Ramos Castro (Ed.), Advances in speech and language technologies for iberian languages: IberSPEECH 2012, Conference Proceedings (pp. 227?236). Springer. https://doi.org/10.1007/978-3-642-35292-8_24