Lan X Chen1, H Ralph Schumacher. 1. Rheumatology Division, School of Medicine, University of Pennsylvania Medical Center-Presbyterian and VAMC, 3600 Spruce Street, Philadelphia, PA 19104, USA. chenlx@mail.med.upenn.edu
Authors: Jorge Vas; Camila Méndez; Emilio Perea-Milla; Evelia Vega; María Dolores Panadero; José María León; Miguel Angel Borge; Olga Gaspar; Francisco Sánchez-Rodríguez; Inmaculada Aguilar; Rosario Jurado Journal: BMJ Date: 2004-10-19