Lea, R.M.: 'The comparative cost of associative memory', Radio and Electronic Engineer, 1976, 46, (10), p. 487-496, DOI: 10.1049/ree.1976.0072
IET Digital Library, https://digital-library.theiet.org/;jsessionid=3ehfxv4ir4pp.x-iet-live-01content/journals/10.1049/ree.1976.0072