4Chifflot H,Fautzi B,Sorder C,et al.Incidence and prevalence of systemic sclerosis:a systematic literature review[J].Semin Arthritis Rheum,2008,37(4):223-235.
5Derk CT,Huaman G,Jimenez SA.A retrospective randomly selected cohort study of D-penicillamine treatment in rapidly progressive diffuse cutaneous systemic sclerosis of recent onset[J].Br J Dermatol,2008,158(5):1063-1068.
6Khanna D,Furst DE,Hays RD,et al.Minimally important difference in diffuse systemic sclerosis:results from the D-penicillamine study[J].Ann Rheum Dis,2006,65(10):1325-1329.