Franklin JM, Dejene S, Huybrechts KF, Wang SV, Kulldorff M, Rothman KJ. A bias in the evaluation of bias comparing randomized trials with nonexperimental studies. Epidemiol Methods. 2017 Apr;6(1):20160018.. doi: 10.1515/em-2016-0018.
Fortuny J, Kogevinas M, Zens MS, Schned A, Andrew AS, Heaney J, Kelsey KT, Karagas MR. Analgesic and anti-inflammatory drug use and risk of bladder cancer: a population based case control study. BMC Urol. 2007 Aug 10;7:13. doi: 10.1186/1471-2490-7-13