Schnitzer, T. J., Hochberg, M. C., Marrero, C. E., Duquesroix, B., Frayssinet, H., Beekman, M. Efficacy and safety of naproxcinod in patients with osteoarthritis of the knee: a 53-week prospective randomized multicenter study. Seminars in Arthritis & Rheumatism 2011; 4: 285-97