Ehrich EW,Schnitzer TJ,McIlwain H,Levy R,Wolfe F,Weisman M,Zeng Q,Morrison B,Bolognese J,Seidenberg B,Gertz BJ. Effect of specific COX-2 inhibition in osteoarthritis of the knee: a 6 week double blind, placebo controlled pilot study of Rofecoxib . Rofecoxib Osteoarthritis Pilot Study Group. J Rheumatol 1999;26(11):2438-2447.