^Kano, Noriaki. Attractive quality and must-be quality. The Journal of the Japanese Society for Quality Control. 1984-04-01: 39–48.
^Pirsig, Robert M. Zen and the art of motorcycle maintenance : an inquiry into values. New York, N Y: Morrow. 1974. ISBN0688002307. Cited by: Jones, D.R. Exploring quality: what Robert Pirsig's "Zen and the art of motorcycle maintenance" can teach us about technical communication. IEEE transactions on professional communication (IEEE). September 1989, 32 (3): 154–158.