* John Shorter, 2000, "The prehistory of the Hammett equation," Chem. Listy, 94:210-214.
* Frank Westheimer, 1997, "Louis Plack Hammett, 1894—1987: A Biographical Memoir," pp. 136–149, in Biographical Memoirs, Washington, DC, US: National Academies Press, see [http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/hammett-louis-p.pdf], accessed 22 June 2015.