D. S. Entraining tones and binaural beats [Internet]. Mind Alive Inc.; 2009 . http://mindalive.com/default/assets/File/article%2012.pdf

D. S. Audio-visual entrainment: history and physiological mechanisms. Association for applied psychophysiology and biofeedback. Biofeedback magazine [Internet]. 2003;31(2). https://goo.gl/EDwhN2