STANKIEWICZ, B., ZIELIŃSKI, K., DAROWSKI, M., & MICHNIKOWSKI, M. (2015). EtCO2-Based Biofeedback Method of Breath Regulation Increases Speech Fluency of Stuttering People. Archives of Acoustics, 40(4), 469–474. https://doi.org/10.1515/aoa-2015-0046