1. Scleroderma Program, University of Michigan, Ann Arbor, MI, USA
2. Department of Rheumatology, University Hospital Zurich, Zurich, Switzerland
3. Department of Rheumatology A, Cochin Hospital, Paris Descartes University, Paris, France
4. Centre for Rheumatology and Connective Tissue Diseases, Royal Free Hospital, London, UK
5. Division of Rheumatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA