Editing Hermann von Helmholtz (section)

=== Sources ===
* Cahan, David ''Helmholtz: A Life in Science.''    University of Chicago Press, 2018.  {{ISBN|978-0-226-48114-2}}.
* Cohen, Robert, and [[Marx W. Wartofsky|Wartofsky, Marx]], eds. and trans. Reidel. ''Helmholtz: Epistemological Writings'', 1977.
* Ewald, William B., ed. ''From Kant to Hilbert: A Source Book in the Foundations of Mathematics'', 2 vols. Oxford Uni. Press, 1996.
** 1876. "The origin and meaning of geometrical axioms", 663–88.
** 1878. "The facts in perception", 698–726.
** 1887. "Numbering and measuring from an epistemological viewpoint", 727–52.
* Groundwater, Jennifer. ''Alexander Graham Bell: The Spirit of Invention''. Calgary: Altitude Publishing, 2005. {{ISBN|1-55439-006-0}}.
* Jackson, Myles W. ''Harmonious Triads: Physicists, Musicians, and Instrument Makers in Nineteenth-Century Germany'' (MIT Press, 2006).
* Kahl, Russell, ed. Wesleyan. ''Selected Writings of Hermann von Helmholtz'', Uni. Press., 1971.
* Koenigsberger, Leo. ''Hermann von Helmholtz'', translated by Frances A. Welby (Dover, 1965)
* MacKenzie, Catherine. [https://books.google.com/books?id=iFOcw4lN_ZYC ''Alexander Graham Bell''.] Whitefish, Montana: Kessinger Publishing, 2003. {{ISBN|978-0-7661-4385-2}}. Retrieved 29 July 2009.
* Shulman, Seth. ''[[The Telephone Gambit]]: Chasing Alexander Bell's Secret''. New York: Norton & Company, 2008. {{ISBN|978-0-393-06206-9}}.