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Li Q, Tso GK, Qin Y, Lovejoy TI, Heckman TG, Li Y.Li Q, et al.Stat Methods Med Res. 2019 Oct-Nov;28(10-11):3205-3225. doi: 10.1177/0962280218797148. Epub 2018 Sep 19.Stat Methods Med Res. 2019.PMID: 30229703
Morasco BJ, Lovejoy TI, Lu M, Turk DC, Lewis L, Dobscha SK.Morasco BJ, et al.Pain. 2013 Apr;154(4):609-616. doi: 10.1016/j.pain.2013.01.001. Epub 2013 Jan 11.Pain. 2013.PMID: 23398939Free PMC article.