Arellano FM, Yood MU, Wentworth CE, Oliveria SA, Rivero E, Arana A, Rothman KJ. Use of Cyclo-Oxygenase 2 Inhibitors (COX-2) and prescription Non-Steroidal Anti-Inflammatory Drugs (NSAIDS) in UK and USA populations. Pharmacoepidemiol Drug Saf. 2008 Oct 1;17(10):1037. doi: 10.1002/pds.1636