Cohen, Annabel J., Michael Lamoureux, Richard Fleming, and Debora Dunphy. “Judged Direction of Pairs of Octave-Related Complexes (Shepard tones): Training Effects and Reversal”. Canadian Acoustics 26, no. 3 (September 1, 1998): 58-59. Accessed June 23, 2021. https://jcaa.caa-aca.ca/index.php/jcaa/article/view/1156.