1. Barker, A.: Harmonics in Classical Greece. Cambridge University Press, Cambridge (2007)
2. Heller-Roazen, D.: The Fifth Hammer. Pythagoras and the Disharmony of the World, Zone Books, New York
3. Watkins, M.: Prime evolution (interview). Collapse 1(1), 93–189 (2006)
4. Gilmore, B.: Clarence Barlow interviewed by Bob Gilmore, Amsterdam, 1st August 2007, Paris Atlantic Magazine (2015).
www.paristransatlantic.com/magazine/interviews/barlow.html
5. Lach, J.S.: Harmonic Duality. From interval ratios and pitch distance to spectra and sensory dissonance, Leiden University (2012)