Rakowski, Andrzej, and Piotr Rogowski. “Investigating the Pitch Strength of Short Pur E-Tone Pulses in Middle Frequency Range through Their Chroma Recognition by Absolute-Pitch Listeners”. Interdisciplinary Studies in Musicology, vol. 8, Oct. 2018, pp. 271-8, https://pressto.amu.edu.pl/index.php/ism/article/view/14918.