Regier DA, Sicsic J, Watson V. Choice certainty and deliberative thinking in discrete choice experiments. A theoretical and empirical investigation. J Econ Behav Organ. 2019 Aug;164:235-55. doi: 10.1016/j.jebo.2019.05.031
Engelhart L, Nelson L, Lewis S, Mordin M, Demuro-Mercon C, Uddin S, McLeod L, Cole B, Farr J. Knee injury and osteoarthritis outcome score subscales for patients with articular cartilage lesions of the knee. Am J Sports Med. 2012 Oct 1;40(10):2264-72.