The Mayo Clinic-Canadian Cooperative trial of sulfasalazine in active multiple sclerosis. by Noseworthy, J, O'Brien, P, Erickson, B, Lee, D, Sneve, D, Ebers, G, Rice, G, Auty, A, Hader, W, Kirk, A, Duquette, P, Carter, J, Francis, G, Metz, L, Shuster, E