Churchman, C. West (December 1967). “Wicked Problems”. Management Science14 (4): B-141-B-146. doi:10.1287/mnsc.14.4.B141.
Skaburskis, Andrejs (19 December 2008). “The origin of "wicked problems"”. Planning Theory & Practice9 (2): 277–280. doi:10.1080/14649350802041654. "At the end of Rittel's presentation, West Churchman responded with that pensive but expressive movement of voice that some may well remember, 'Hmm, those sound like "wicked problems."'"