A prospective, open-label treatment trial to compare the effect of IFNbeta-1a (Avonex), IFNβ-1b (Betaseron), and glatiramer acetate (Copaxone) on the relapse rate in relapsing-remitting multiple sclerosis: results after 18 months of therapy. - Khan,O.A.; Tselis,A.C.; Kamholz,J.A. (Mult Scler, 2001)